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A general solution for a thermoviscoelastic trimaterial combined with a point heat source and a point heat sink is presented in this work. Based on the method of analytic continuation associated with the alternation technique, the solutions to the heat-conduction and thermoelastic problems for three dissimilar, sandwiched media are derived. A rapidly convergent series solution for both the temperature and stress field, expressed in terms of an explicit general term of the corresponding homogeneous potential, is obtained in an elegant form. The hereditary integral in conjunction with the Kelvin–Maxwell model is applied to simulate the thermoviscoelastic properties, while a thermorheologically simple material is considered. Based on the correspondence principle, the Laplace transformed thermoviscoelastic solution is directly determined from the corresponding thermoelastic one. The real-time solution can then be solved numerically by taking the inverse Laplace transform. A typical example concerning the interfacial stresses generated from a combined arrangement of a heat source and sink are discussed in detail. The corresponding thin-film problem is also discussed.

Advancements in automated high-performance thin-layer chromatography (HPTLC) have made it feasible to assess its use for the quantitative analysis of marker compounds in botanical preparations. We report here the findings of method comparisons for the terpenelactones and flavonol aglycones by column high-performance liquid chromatography (HPLC) with evaporative light scattering and UV detection, and HPTLC with a scanning densitometer. For the HPTLC assay of terpenelactones, total bilobalide, ginkgolide A, and ginkgolide B consistently achieved

Background: Prior improvement work integrating standardized medical discharge criteria in general pediatric inpatients led to improved discharge timeliness and reduced length of stay (LOS). Our aim was to develop standardized medical discharge criteria on a quaternary pediatric cardiology unit in an effort to improve the timeliness of discharge. We hypothesized that timely discharge would lead to cost savings and a reduced LOS. Methods and Results: Over 18 months (Jan. 2014 - June 2015), a multi-disciplinary team worked toward the quality improvement aim of increasing the percentage of pediatric cardiology inpatients discharged within 2 hours of achieving medical discharge criteria. We established preset ‘medically ready’ discharge criteria in our hospital EMR, initiated upon admission for all inpatients and modified daily as needed. We organized criteria into 7 categories (congenital heart disease (CHD) medical, CHD post-operative, heart failure/transplant medical, transplant post-operative, electrophysiology (EP) medical, EP post-procedure, and catheterization post-procedure). The median percentage of patients discharged within 2 hours of meeting criteria increased steadily from 35% to 78% over the project period. Concurrently, the median number of patients discharged before noon increased from 18% to 31%. Physician and nursing compliance with necessary process measures was 87% and 89%, respectively. LOS decreased by 8% (3.6 to 3.3 days) from the first 6 months of work to the last 6 months. All-cause readmission remained stable at 15% over the improvement time frame. Review of inpatient charges between Oct. 2014 and June 2015 demonstrated 169 patients (190 discharges) who experienced a delayed discharge based on the set criteria. The sum of charges from care provided after meeting criteria was $231,201 (average of $1,217 per delayed discharge). Conclusions: Discharge timeliness in pediatric cardiology patients can be improved by standardizing medical discharge criteria. We demonstrate that this can be achieved across all subcategories of pediatric cardiology without increasing the rate of readmission. Improved discharge timeliness not only reduces LOS; it provides an opportunity to substantially decrease medical charges.

Background There is considerable interest from a regulatory and public health perspective in harmful and potentially harmful constituents in tobacco products, including smokeless tobacco products (STPs). A wide range of commercial STPs from the US and Sweden, representing 80–90 % of the 2010 market share for all the major STP categories in these two countries, were analysed for the IARC Group 2A carcinogen acrylamide. These STPs comprised the following styles: Swedish loose and portion snus, US snus, chewing tobacco, moist snuff, dry snuff, soft pellet, hard pellet and plug. Results Acrylamide was detected in all the products tested and quantified in all but one product. Concentrations ranged from 62 to 666 ng/g wet weight basis (WWB). The average levels of acrylamide (WWB) by type of STP were not significantly different (p > 0.05) except for US snus which had, on average, greater levels but with a very wide range of individual levels according to the manufacturer. Acrylamide levels in STPs were significantly and positively correlated with pH, but not with levels of either reducing sugars or ammonia nitrogen. Levels of acrylamide increased by sixfold or more (on a dry weight basis) during manufacture of a snus sample and then decreased during subsequent storage for up to 22 weeks. Acrylamide generation in tobacco generally appears to occur at lower temperatures, but longer time scales than found with food production. Conclusions Acrylamide is a common contaminant of STPs, formed through heat treatment of tobacco. Our data show that exposure to acrylamide from consumption of STPs is small compared with exposure from food consumption or cigarette smoking. Electronic supplementary material The online version of this article (doi:10.1186/s13065-015-0132-1) contains supplementary material, which is available to authorized users.

To assess whether adequate post-discharge venous thromboembolism (VTE) prophylaxis is prescribed to patients who underwent hip fracture surgery (HFS) and to consider what should be prescribed to patients who are already taking antiplatelet agents. A retrospective study analysed discharge

We present the results of an investigation into strategies for the introduction of OpenMP to the NEMO oceanographic code. At present NEMO is parallelized using only the Message Passing Interface (MPI) with a two-dimensional domain decomposition in latitude/longitude. This version performs well on core counts of up to a few thousand.

Background Due to the lower health risks associated with the use of certain categories of smokeless tobacco products (STPs) such as Swedish snus, there is interest in the comparative levels of toxic chemical constituents in different types of STPs. A method has been developed and validated for the analysis of hydrazine in STPs. Seventy four commercial STPs from the US and Sweden, representing 80-90% of the 2010 market share for all the major STP categories in these two countries, as well as three reference STPs, were analysed for hydrazine. Results Aqueous extracts of the STPs were treated with excess pentafluorobenzaldehyde (PFB), which reacted with hydrazine in solution to form decafluorobenzaldehyde azine (DFBA). DFBA was partitioned into hexane and then quantified by gas chromatography–mass spectrometry (GC–MS). The method was validated using five different types of STP, was linear in the range 8–170 ng/mL, and had limits of quantification (LOQ) from 26–53 ng of hydrazine per g of STP (as sold). The method was applied to the analysis of 74 contemporary STPs commercially available in the United States and Sweden, none of which were found to contain hydrazine above the LOQ or LOD. Trace levels of compounds showing chromatographic and mass spectral features consistent with hydrazine were identified at very low levels (sub-limit of detection

Background and purpose: Diffusion-weighted imaging using echo-planar imaging (EPI) is prone to geometric inaccuracy, which may limit application to image-guided radiation therapy planning, as well as for voxel-based quantitative multi-parametric or multi-modal approaches. This research investigates pelvic applications at 3 T of a standard single-shot (ssEPI) and a prototype readout-segmented (rsEPI) technique. Materials and methods: Apparent diffusion coefficient (ADC) accuracy and geometric performance of rsEPI and ssEPI were compared using phantoms, and in vivo, involving 8 patients prior to MR-guided brachytherapy for locally advanced cervical cancer, and 19 patients with prostate cancer planned for tumor-targeted radiotherapy. Global and local deviations in geometric performance were tested using Dice Similarity Coefficients (DC) and Hausdorff Distances (HD). Results: In cervix patients, DC increased from 0.76 +/- 0.14 to 0.91 +/- 0.05 for the high risk clinical target volume, and 0.62 +/- 0.26 to 0.85 +/- 0.08 for the gross tumor target volume. Tumors in the peripheral zone of the prostate gland were partly projected erroneously outside of the posterior anatomic boundary of the gland by 3.1 +/- 1.6 mm in 11 of 19 patients using ADC-ssEPI but not with ADC-rsEPI. Conclusions: Both cervix and prostate ssEPI are prone to clinically relevant geometric distortions at 3 T. rsEPI provides improved geometric performance without post-processing.

Recent research in software engineering has highlighted the need to ensure alignment between business objectives, customer requirements and product development. If the business is to meet its strategic objectives, the Requirements Engineering (RE) activities must be executed in a manner such that they support these higher level objectives. A clear alignment between RE activities and the strategic objectives of the organization should underscore the merit of IT investment and the opportunities for competitive advantage that can be pursued as a result by the organization. This research begins with a detailed investigation of the complexity of decision-making during RE activities on business, product and project levels. Secondly, it investigates "in-project" level RE decisions and provides empirical findings from an industrial case study. The findings show that RE project related decisions are influenced by business and product requirements. Although the software developers in this study recognized the importance of developing software products that meet customer requirements and that are aligned with business objectives, they found it difficult to achieve this when the customer was external and the communication was a major problem. A lack of understanding the business strategy and a lack of communication between business, product and project level stakeholders were among the problems that are highlighted by this study.

We report here a liquid chromatography (LC) method with inline ultraviolet/evaporative light scattering (UV/ELS) detection for the simultaneous quantification of the terpenelactones and flavonol aglycones in a single sample of hydrolyzed Ginkgo biloba extract (GBE). The sample is hydrolyzed by a rapid and convenient oven heating method for 1 h at 90°C with 10% hydrochloric acid. The 1 h hydrolysis was found to be equivalent to the 2.25 h reflux treatment for dry powder extract, where total flavonol glycosides were 28.4 and 28.1%, respectively. Acceptable precision was achieved for total terpenelactones [relative standard deviation (RSD) = 4.8%] by ELS detection, and total flavonol aglycones (RSD = 2.3%) by UV detection. The analytical range was 1.5 to 7.3% (w/w) for the individual terpenelactones (ELS) and 2.5 to 15.0% (w/w) for the individual glycosides (UV) calculated from the aglycones quercetin, kaempferol, and isorhamnetin. This improved method allows for the first time high throughput sample preparation coupled with the quantification of the predominant compounds generally used for quality control of GBE in a single assay.

Previous work has shown the feasibility of removing polyphenols from tobacco extracts by electrodialysis using monopolar membranes. However, the low migration rates obtained for polyphenols were not sufficient to demonstrate that it was a practical technology. In the present work three anionic membranes of the same type, AM-4 or AM-2, were stacked in a cell and the duration of treatment was extended to 4 h. Trends previously observed during electromigration treatments for these membranes were confirmed. The AM-4 and AM-2 membranes gave final demineralization rates of 86.5 and 89.5%, respectively. High polyphenol migration rates were obtained with these membranes: for the AM-4 and AM-2 membranes the rates were, respectively, for chlorogenic acid 90.8 and 86.5%, for scopoletin 66.7 and 23.2%, and for rutin 81.3 and 31.1%. These results confirmed that ED has the potential for efficient separation of tobacco polyphenols. However, for both membranes, the mass balance showed a large (90%) decrease in nicotine in the treated tobacco extract, indicating a high level of nicotine electromigration. Measurements of the membrane characteristics before and after treatment were consistent with the AM-2 membrane becoming fouled during treatment.

Polyphenols in tobacco are known precursors for bioactive phenolic compounds in cigarette smoke. Electrodialysis has been tested as a means of selectively extracting polyphenols from aqueous tobacco extracts. Seven commercial membranes were tested in an electromigration configuration. This exploratory study showed the potential application of AM-2 and AM-4 membranes for the migration of polyphenols. During 3-h trials with a single membrane in an electrodialysis cell, both AM-2 and AM-4 membranes achieved a 77% demineralization rate. The migration rates for the AM-2 and AM-4 membranes were for chlorogenic acid 24.7 and 28.7%, respectively, for scopoletin 8.6 and 18.8%, and for rutin −10.3 and 10.3%.

Preparations from comfrey (Symphytum officinale and S. x uplandicum) root and leaf contain varying levels of the hepatotoxic pyrrolizidine alkaloids (PAs). Reference compounds for comfrey are not commercially available, and there is currently no rapid extraction or analytical method capable of determining low levels in raw materials or as adulterants in commercially available extracts. A solid-phase extraction (SPE) method was developed using an Ergosil cleanup column that specifically binds the PAs. With this method, powdered comfrey root was extracted by sonication and shaking with basic chloroform. The extract was applied to the cleanup column under vacuum, washed with 2 mL acetone–chloroform (8 + 2, v/v) followed by 2 mL petroleum ether to remove excess chloroform. The column was dried under vacuum, and the PAs were eluted with 2 successive 1 mL aliquots methanol. Percent recoveries of the PAs following Ergosil SPE had an overall average of 96.8%, with RSD of 3.8% over a range of 1.0 to 25.0 g extracted in 100 mL. Average precision of the method (n = 3 over 4 extraction concentrations) gave an overall RSD of 6.0% for the 5 alkaloids, with a range of 0.8% (5 g in 100 mL) to 11.2% (25 g in 100 mL). Recovery optimization testing showed that 1.0 g comfrey root extracted in 100 mL yielded the greatest recovery (% dry weight) of the PAs, with an extraction efficiency and accuracy of 94.2%, and RSD of 1.7% (n = 9). The unique properties of the Ergosil cleanup column provide rapid sample cleanup, volume reduction, and concentration of PAs from comfrey extracts, and allow the eluant to be analyzed directly by traditional chromatographic methods.

In the Introduction to his lectures on the modern British missionary movement published in 1965, Max Warren suggested that “any serious student of modern history must find some explanation of the missionary expansion of the Christian Church.” Many, perhaps most, scholars have ignored his advice, and until very recently, it would have been difficult to persuade researchers in the modern academic mainstream to take such an injunction seriously, so flatly would it have seemed to contradict or question the dominant assumptions of liberal, secular scholarship. The progress of an all-pervasive secularization meant that missions, if not the churches both that supported them and that they hoped to build, were to be listed amongst history's losers and were therefore unattractive subjects for study.

These days’ technologies offer new channels to reach public and market, the convergence between the various communications fields increases which is in marketing public relations strategies used to for developing a brand awareness the product such as coffee products. This paper likewise provides a solution to develop a brand awareness via media store sellers who might help the company to promote their products in light of consumer behavior. In this study, one hundred and fifteen questionnaires, on facilities available in the society, and technology distributed online, and it focuses on generations millennial in Taiwan. The purpose of the survey will focus on coffee products from Indonesia which is called Coffindo Nusantara from Coffindo Company.

A shape-memory alloy, nickel–titanium (NiTi), has been distributed throughout an aluminum matrix, using powder-metallurgy processing, in the hope of using the shape-memory effect to achieve strengthening and improve the fatigue resistance, as compared with the aluminum matrix. The shape-memory effect was activated by cold rolling the samples at −30°C. Upon reheating to the austenite phase, the NiTi was expected to return to its original shape, while embedded in the aluminum matrix. This action created residual, internal stresses around each particle, which strengthened the material. The yield and ultimate strengths, and fatigue lives of the NiTi reinforced aluminum composites, have been improved considerably, as compared with the unreinforced material. The cross-sectional microstructures of the composites, as well as, the modes of crack growth, have been examined with scanning electron microscopy (SEM) to identify fatigue and fracture mechanisms.

(2001). Sir roger casement and the international humanitarian movement. The Journal of Imperial and Commonwealth History: Vol. 29, No. 2, pp. 59-74.

We investigate the influence of taper geometry in Er/Yb co-doped fiber (EYDF) strain sensors using tunable abrupt-tapered Mach-Zehnder interferometers (AT-MZI). It was found that the sensitivity of the strain sensor can be enhanced by reducing both the waist diameters of, and the span between the two abrupt tapers. For strains under 0.2% in AT-MZIs with a consistent span of 10 mm, the strain-induced interference wavelength shift increases from 0.5 nm to 8.4 nm as the average waist diameter of the two abrupt tapers decreases from 62.58 μm to 24.58 μm. Those AT-MZIs with a greater span between the abrupt tapers or a greater difference between the two taper waist diameters display a decreased sensitivity. It is also shown that the span between tapers in inversely proportional to the free spectrum range and the extionction ratio.

Children who have suffered extensive unilateral brain injury early in life may show a remarkable degree of residual sensorimotor function. It is generally believed that this reflects the high capacity of the immature brain for cerebral reorganization. In this study, we investigated 17 patients who had undergone hemispherectomy for relief from seizures; eight of the patients had congenital brain damage and nine had sustained their initial insult at the age of 1 year or older. Sensorimotor functions of the hand were investigated using functional MRI (fMRI) during a passive movement task, somatosensory evoked potentials (SEPs) arising from electrical and vibration stimulation, and behavioural tests including grip strength, double simultaneous stimulation and joint position sense. On fMRI, two of the eight patients studied with this technique (one with congenital damage and one with damage acquired at the age of 3 years) showed activation in the sensorimotor cortex of the remaining hemisphere with passive movement of the hemiplegic hand. The location of the ipsilateral brain activation was similar to that found on movement of the normal contralateral hand, although the latter was greater in spatial extent. In one of these patients, a greater role was demonstrated for the ipsilateral secondary sensorimotor area (compared with the ipsilateral primary sensorimotor area) for movement of the hemiplegic hand than for movement of the normal hand. Median nerve stimulation of the hemiplegic hand showed reproducible early-latency ipsilateral SEP components in the remaining sensorimotor cortex in 10 of the 17 patients (five with congenital and five with acquired disease). Five of the patients who demonstrated ipsilateral electrical SEPs also showed ipsilateral vibration SEPs (two with congenital and three with acquired disease). The behavioural tests revealed residual sensorimotor function in 14 of the patients; however, not all of the patients who exhibited ipsilateral SEP or fMRI responses had residual sensorimotor function in the hemiplegic hand. Ipsilateral sensorimotor responses were demonstrated both in patients with congenital disease and those with acquired disease, suggesting that factors additional to aetiology and age at injury may influence the degree of residual sensorimotor function and cerebral reorganization.

Historians' perceptions of the significance of the South African War (1899-1902) have changed considerably over a century. For a long time, its military magnitude, its importance in shaping a global capitalist system, and the stimulus it provided to theoretical understanding of imperialism, were felt to give the war an important role in the making of the modern world. Recent perspectives, both fed by and represented in the centenary commemorations, have replaced these grand sweeps with attention to the many and detailed South African wars experienced at first hand by different individuals and segments of Britain's and South Africa's populations. There is a case for suggesting that the place of the war in Britain's broader domestic and imperial history is now and perhaps rightly-neglected, in part as a consequence of the fragmentation encouraged by historiographical specialization and also because an exaggerated importance was attributed to it for so long. THE MILLENNIUM LECTURES organized by the Historical Association aim to mark significant events of the past which also have an anniversary connection to the year in which the lecture is given. In accepting the Association's invitation, it was difficult for an imperial historian with my record to escape the subject of the South African, or Boer, War. That conflict started on 1 1 October 1899 and preoccupied Britain for some two and a half years, until a peace treaty was agreed at Vereeniging on the Vaal River on 23 May 1902. Still more to the point is that today coincides directly with the centenary of what was at the time rapidly christened 'Black Week'. On 10 December 1899 at Stormberg railway junction in the eastern Cape Colony, on the following day at Magersfontein Hill in the west of the Orange Free State, and on 15 December at Colenso on the Tugela River in Natal, imperial forces were defeated with heavy losses. In these major engagements on each of the three principal fronts of the war, Lt-General Sir William Gatacre, Lord Methuen, and the overall commander General Sir Redvers Buller not only lost almost 10 percent of their troops to Boer forces perhaps two-thirds their size, but damaged their own military reputations virtually beyond repair. Lords Roberts and Kitchener were Andrew Porter is Rhodes Professor of Imperial History at King's College, London. This article is the text of a public lecture given at the Society of Antiquaries, Burlington House, London on 10 December 1999.

We recently reported on three young patients with severe impairments of episodic memory resulting from brain injury sustained early in life. These findings have led us to hypothesize that such impairments might be a previously unrecognized consequence of perinatal hypoxic-ischaemic injury. Neuropsychological and quantitative magnetic resonance investigations were carried out on five young patients, all of whom had suffered hypoxic-ischaemic episodes at or shortly after birth. All five patients showed severe impairments of episodic memory (memory for events), with relative preservation of semantic memory (memory for facts). However, none had any of the major neurological deficits that are typically associated with hypoxic-ischaemic injury, and all attended mainstream schools. Quantitative magnetic resonance investigations revealed severe bilateral hippocampal atrophy in all cases. As a group, the patients also showed bilateral reductions in grey matter in the regions of the putamen and the ventral part of the thalamus. On the basis of their clinical histories and the pattern of magnetic resonance findings, we attribute the patients' pathology and associated memory impairments primarily to hypoxic-ischaemic episodes sustained very early in life. We suggest that the degree of hypoxia-ischaemia was sufficient to produce selective damage to particularly vulnerable regions of the brain, notably the hippocampi, but was not sufficient to result in the more severe neurological and cognitive deficits that can follow hypoxic-ischaemic injury. The impairments in episodic memory may be difficult to recognize, particularly in early childhood, but this developmental amnesia can have debilitating consequences, both at home and at school, and may preclude independent life in adulthood.

In the early years of the modern missionary movement there were many influences which turned minds towards support for the general principle and practice of reliance on ‘native agency’. Strategies of conversion such as those of the London Missionary Society and the American Board of Commissioners for Foreign Missions at work in the Pacific, which aimed at kings or other influential local leaders, at least implicitly allotted important roles to the leadership and example of highly-placed converts. Awareness of the scale of the missionary task in densely-populated regions, contrasted with the limits of the western missionary input, pointed to the need for delegation as quickly as possible. The Serampore missionaries, Alexander Duff and Charles Gutzlaff, all travelled early down that road. Financial crisis – manifested either locally as Dr John Philip found in South Africa, or centrally as when the Church Missionary Society decided in the early 1840s to withdraw from the West Indies - prompted inevitable questions about the possibilities for deployment of local agents, who were far cheaper than Europeans.

ANDREW PORTER [**] Today's commemoration is designed to mark the bicentenary of the Church Mission Society. (CMS), the 'Society for Missions to Africa and the East' as it was originally and, with its geographical pointers, somewhat unusually called until 1812. Today's theme, 'changing people, changing places', is sufficiently ample-- or perhaps conveniently ambiguous -- as to allow for almost any survey of past achievements and future prospects both appropriate to such a celebration and in keeping with many earlier May meetings. And its setting, here in Holy Trinity church, cannot but prompt recollections of the striking continuities which, quite as much as change, have marked the relationship between Cambridge and the CMS ever since the Society's formation. The university, the town, and the surrounding region have always been linked in a host of institutional and familial ways. Looking back for a moment to 1899, it is difficult not to be struck by the contrasting character of events then and those of today. We are told: The Centenary was a busy time...as a whole week was filled up with meetings and gatherings. There was a United Service at Great St Mary's, when the Bishop of Ripon...preached a sermon of riveting eloquence. The Mayor and Corporation attended in state. The Mayor...gave a reception in the Guildhall before the great evening meeting, and at the concluding service in Ely Cathedral there was large congregation, including a strong contingent from Cambridge, the preacher being [the] President of Queen's and Hulsean Professor of Divinity. The Master of St John's gave a Breakfast to a large company of University guests; and a crowded service in Great St Mary's for children gathered from all the Parochial Sunday Schools in the town marked the Sunday afternoon. The Centenary Fund amounted to [pounds]560.[1] Consider 1999. There is still the civic presence and evensong in Great St. Mary's. But now there is also a tent on Clapham Common, a perambulating camel, and here no sermon, only an address, and that from no preacher or theological scholar. Indeed, CMS might seem to have forgotten its first centennial encounter with King's College, London. The Lecturer in Ecclesiastical History at King's, the Reverend Charles Hole, commissioned eight years in advance to produce a centenary history, had by 1898 completed his study only as far as 1814. As a result the Society had to turn to its own, calling its Secretary, Eugene Stock, to its rescue.[2] Hole's embarrassment, Stock's monumental achievement (eventually running to four volumes), and a further two volumes from Gordon Hewitt covering the years 1910 to 1942, are each in their different ways testimony to the difficulty of doing justice to the Society's past. [3] In such circumstances, with Ward's and Stanley's bicentennial book almost upon us, to invite not one of King's theologians but its Rhodes Professor of Imperial History even to speak, might seem quixotic. [4] Cecil Rhodes - diamond digger, opportunist politician, unscrupulous financier, overgrown schoolboy, charismatic visionary or megalomaniacal rogue according to taste - was, even as son of the vicar of Bishop's Stortford, somewhat unorthodox in religious outlook. Appropriating missionary rhetoric about civilization, he equally readily exploited missionary contacts for his own plans to change people and places. He was reported as saying: If there be a God and He cares anything about what I do, I think it is clear that He would like me to do what He is doing himself...to paint as much of the map of Africa British red as possible, and to do what I can elsewhere to promote the unity and extend the influence of the English-speaking race. [5] I can only reassure you and provide perhaps some slight safeguard for today's proceedings by saying that holders of the chair carrying his name are not required to submit to any of his religious tests. However, in at least one respect, the outlooks of Rhodes and many a nineteenth-century CMS missionary seem all too similar. …

Single-shot diffusion-weighted echo-planar imaging (EPI) is typically used for most clinical diffusion studies due to its low sensitivity to patient motion. Although the Nyquist ghost artifact in EPI can be substantially reduced, there is frequently a residual ghost with low signal intensity. As reported in this study, this residual ghost can produce severe artifacts when maps of the apparent diffusion coefficient (ADC) are calculated from single-shot echo-planar images. The artifacts presented in this paper appear as regions of apparently low ADC which simulate regions of reduced diffusion, but are in fact generated by b-value dependent Nyquist ghosts of the orbits. Data acquired in vivo were used to demonstrate that these artifacts can be avoided by including standard methods of spatial presaturation or fluid-suppression in the diffusion-weighted EPI protocol. In addition, phantom studies were used to illustrate how phase and amplitude variations in the ghost generate the artifacts and theoretical expressions, derived elsewhere, were used to provide a detailed understanding of the artifacts observed in vivo. The level of Nyquist ghost reported for the current generation of commercial scanners suggests that this is a general phenomenon which should be a consideration in all EPI-based diffusion studies. Magn Reson Med 42:385-392, 1999. (C) 1999 Wiley-Liss, Inc.

Multislice echo-planar imaging (EPI) is a commonly used technique for fMRI studies. Brain activation images acquired using fMRI are sensitive to T2* changes, reflecting the level of blood oxygenation (BOLD contrast), and may also contain an element of T1 contrast which detects blood flow changes in large vessels. If slice inflow (T1) effects are significant in multislice EPI, then as the order in which the slices are acquired is changed, differences in the activation maps are predicted. However, in experiments presented here using visual stimulation, the data demonstrate that highly consistent results can be achieved for repetition times (TR) of 6.0, 3.0, and 1.5 s. This suggests that, for whole-brain multislice EPI, fMRI activation is dominated by T2*, BOLD contrast. The thickness of the imaging slice is also an important parameter in these studies, having implications for spatial resolution, sensitivity, and acquisition time. In separate visual cortex experiments the effect on the values of the fMRI Z scores and the number of activated voxels is investigated as a function of slice thickness (from 1 to 8 mm). The maximum Z scores in the data are similar for all slice thicknesses and, after resampling to allow a direct comparison to be made, the volume of visual cortex detected as significantly activated increases with slice thickness.

The importance of diffusion-weighted MRI in the assessment of acute stroke is well-recognized, and quantitative maps of the apparent diffusion coefficient (ADC) are now widely used. Echoplanar imaging provides a robust method of acquiring diffusion-weighted images free of motion artifact. However, initial experience with clinical MRI systems indicates that calculation of artifact-free ADC maps from a series of echo-planar diffusion-weighted images is not necessarily straight-forward. One of the problems is that frequency shifts resulting from eddy currents can cause misregistration of base diffusion-weighted images. In this study, an on-line correction method that overcomes this problem is described, and phantom and human images that demonstrate the validity of the technique are presented. The method uses a non-phase-encoded reference scan to correct the phase of each echo in the echo train, and can provide ADC maps that are free of misregistration artifacts, without the need for off-line postprocessing.

(1997). ‘Cultural imperialism’ and protestant missionary enterprise, 1780–1914. The Journal of Imperial and Commonwealth History: Vol. 25, No. 3, pp. 367-391.

The present work reviews related literature and investigates the deposition process and the effects of stress on the electrical and optical properties of ultra-thin electro-optical films (

The purpose of this study was to examine the effects of reductions in blood volume and associated oxygen-carrying capacity on the incidence of plateau at VO2max.Fifteen well-trained athletes (age 23.3 ± 4.5; mass 77.4 ± 13.1 kg, height 180.1 ± 6.0 cm) completed three incremental cycle tests to volitional exhaustion, of which the first was defined as familiarisation, with the remaining two trials forming the experimental conditions of pre- (UBL) and post-(BLE) blood donation (~ 450 cm(3)). The work rate for the incremental tests commenced at 100 W for 60 s followed by a ramp of 0.42 W s(-1), with cadence being held constant at 80 rpm. Throughout all trials, VO2 was determined on a breath-by-breath basis using a pre-calibrated metabolic cart. The criteria for plateau determination was a ∆VO2 ≤ 50 ml min(-1) over the final two consecutive 30 s sampling periods.Despite a significant (P = 0.0028) 9.4 % reduction in haemoglobin concentration and 10.8 % (P = 0.016) reduction in erythrocyte count between UBL and BLE, there was no change in plateau incidence. However, significant differences were observed for both VO2max (P = 0.0059) 51.3 ± 7.6 (UBL) 48.4 ± 7.9 ml kg(-1) min(-1) (BLE) and gas exchange threshold arrival time 383.4 ± 85.2 s (UBL) 349.2 ± 71.4 s (BLE) (P = 0.0028).These data suggest that plateau at VO2max is unaffected by O2 availability lending support to the notion of the plateau being dependent on the anaerobic capacity and the classically orientated concept of VO2max.