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To detect modest associations of dietary intake with disease risk, observational studies need to be large and control for moderate measurement errors. The reproducibility of dietary intakes of macronutrients, food groups and dietary patterns (vegetarian and Mediterranean) was assessed in adults in the UK Biobank study on up to five occasions using a web-based 24-h dietary assessment (n 211 050), and using short FFQ recorded at baseline (n 502 655) and after 4 years (n 20 346). When the means of two 24-h assessments were used, the intra-class correlation coefficients (ICC) for macronutrients varied from 0·63 for alcohol to 0·36 for polyunsaturated fat. The ICC for food groups also varied from 0·68 for fruit to 0·18 for fish. The ICC for the FFQ varied from 0·66 for meat and fruit to 0·48 for bread and cereals. The reproducibility was higher for vegetarian status (κ > 0·80) than for the Mediterranean dietary pattern (ICC = 0·45). Overall, the reproducibility of pairs of 24-h dietary assessments and single FFQ used in the UK Biobank were comparable with results of previous prospective studies using conventional methods. Analyses of diet–disease relationships need to correct for both measurement error and within-person variability in dietary intake in order to reliably assess any such associations with disease in the UK Biobank.
vascular dementia (VaD) and mixed Alzheimer's disease (AD/VaD) are common. How best to monitor treatment is not clear. Our objective was to compare responsiveness and construct validity of change scores, following donepezil treatment, of the standardized Mini-Mental State Examination (sMMSE) and other measures potentially usable in primary care.
A six-month, outcome measurement study. The Disability Assessment for Dementia (DAD), CLOX-1 and 2, Phonetic Fluency, a short Neuropsychiatric Inventory, (the NPI-Q), Clinical Global Impression (CGI) and the SymptomGuide™ (SG) were measured. Construct validity was tested by correlating change scores, and responsiveness by calculating standardized response means (SRMs).
Of 148 treated patients, 116 completed. The mean sMMSE increased by 0.7 (95% Confidence Interval (CI) = -0.005, 1.41; p=0.06; SRM= 0.15). There was no statistically significant difference in the DAD. The NPI-Q (-1.4; 95% CI = -2.08, -0.72; p<0.01; SRM=0.24), ClOX-1 (0.9; 95% CI = 0.19, 1.61; p<0.01; SRM=0.21), ClOX-2 (0.9; 95% CI = 0.17, 1.63; p=0.03; SRM=0.26), Phonetic Fluency (0.9; 95% CI = 0.19, 1.61; p=0.02; SRM=0.21) and SG (0.35; 95% CI = 0.20,0.51; p<0.01; SRM=0.28) each detected significant improvement. The CGI suggested improvement in 74 completers (64%) - mostly “minimal” (44/116, 38%) - while 21/116 (18%) were worse. Change scores at 24 weeks were at best modestly correlated with each other (range -0.22 to 0.30).
Different measures showed different responsiveness, in a setting in which the mean treatment effect seems to have been small, but clinically detectable. Patient-centered and executive function measures might be useful in vascular and mixed dementia.
Non-stoichiometric and impurity doped titanium dioxide materials are good candidates for use in high temperature thermoelectric devices. Nanolayers of non-stoichiometric (TiO2-x) thin films were deposited on Al-foil by atomic layer deposition growth method. X-ray diffraction experiments showed anatase phase for these nanolayers. This crystal structure was maintained even after an annealing treatment of 600 °C for 60 minutes under an O2 pressure of ∼ 10 psi. This investigation presents for the first time how Al-foil can be functionalized by manipulating the Seebeck coefficient of these TiO2-x nanolayers.
Blister-actuated laser-induced forward transfer (BA-LIFT) is a versatile printing technique in which fine jets of ink are ejected from a thin donor film onto an acceptor substrate, enabling high-resolution patterns to be formed. Fluid ejections are initiated by the rapid expansion of micrometre-sized blisters that form on a polymer film underneath the ink layer. Recent work has demonstrated that these ejections exhibit novel flow phenomena due to the unique dimensions and geometry of the BA-LIFT configuration. In this work, we study the dynamics of BA-LIFT printing using a computational model in which fluid is forced by a boundary that deforms according to experimental time-resolved measurements of an expanding blister profile. This allows the model’s predictions to be unambiguously correlated with experimental blister-actuated ejections without any fitting parameters. First, we validate the model’s predictive capabilities against experimental results, including the ability to accurately reproduce the size, shape and temporal evolution of the jet as well as the total volume of ink released. The validated model is then used to interrogate the flow dynamics in order to better understand the mechanisms for fluid ejection. Finally, parametric studies are conducted to investigate the influence of ink density, surface tension, viscosity and film thickness as well as the size of the blister used. These results provide key insights into avenues for optimization and better control of the BA-LIFT process for improved resolution and repeatability of the printed features.
Zinc oxide (ZnO) is a semiconductor that emits bright UV light, with little wasted heat. This intrinsic feature makes it a promising material for energy-efficient white lighting, nano-lasers, and other optical applications. For devices to be competitive, however, it is necessary to develop reliable p-type doping. Although substitutional nitrogen has been considered as a potential p-type dopant for ZnO, recent theoretical and experimental work suggests that nitrogen is a deep acceptor and will not lead to p-type conductivity. In nitrogen-doped samples, a red photoluminescence (PL) band is correlated with the presence of deep nitrogen acceptors. PL excitation (PLE) measurements show an absorption threshold of 2.26 eV, in good agreement with theory. The results of these studies seem to rule out group-V elements as shallow acceptors in ZnO, contradicting numerous reports in the literature. Optical studies on ZnO nanocrystals show some intriguing leads. At liquid-helium temperatures, a series of sharp IR absorption peaks arise from an unknown acceptor impurity. The data are consistent with a hydrogenic acceptor 0.46 eV above the valence band edge. While this binding energy is still too deep for many practical applications, it represents a significant improvement over the 1.4-1.5 eV binding energy for nitrogen acceptors. Nanocrystals present another twist. Due to their high surface-to-volume ratio, surface states are especially important. In our model, the 0.46 eV level is shallow with respect to the surface valence band, raising the possibility of surface hole conduction.
The Expanded Disability Status Scale (EDSS) represents the most widely accepted measure of disease progression in multiple sclerosis (MS), and is used in many natural history studies. This chapter discusses natural history of relapsing onset MS, primary progressive MS, changes in natural history and impact on clinical trial design, traditional prognostic factors, and other factors which may influence prognosis such as race, comorbid diseases, and health behaviors. Pharmacoepidemiological studies using real world data derived from clinical practice represent a cost-effective means of evaluating the long-term effectiveness of immunomodulatory drug treatments for MS. Along with evidence from the basic sciences, epidemiological studies can provide insights into potentially novel treatments, as well as the rationale and hypotheses for testing these treatments in clinical trials. For example, vitamin D and estrogen are being evaluated in clinical trials based partly on epidemiological observations. Heterogeneity remains the hallmark of MS.
Blister-actuated laser-induced forward transfer (BA-LIFT) is a direct-write technique, which enables high-resolution printing of sensitive inks for electronic or biological applications. During BA-LIFT, a polymer laser-absorbing layer deforms into an enclosed blister and ejects ink from an adjacent donor film. In this work, we develop a finite element model to replicate and predict blister expansion dynamics during BA-LIFT. Model inputs consist of standard mechanical properties, strain-rate-dependent material parameters, and a parameter encapsulating the thermal and optical properties of the film. We present methods to determine these material parameters from experimental measurements. The simulated expansion dynamics are shown to be in good agreement with experimental measurements using two different polymer layer thicknesses. Finally, the ability to model high-fluence blister rupture is demonstrated through a strain-based failure approach.
Two-Photon initiated polymerization (TPIP) has shown great promise for fabrication of complex micro- and nano-structures. The method has been used to fabricate such structures over small areas (< 1 mm2) because of slow fabrication speeds and resulting long fabrication times. In order for TPIP to reach practical application in a commercial setting fabrication times need to be reduced by orders of magnitude. We report results on a highly photosensitive initiation system for photoresists based on free radical and cationic polymerization, where photosensitivity is increased 102- to 103-fold compared to previously reported photoinitiation systems. Threshold writing speeds are determined for critical exposure conditions, including laser power, type and concentration of photoinitiation system, and photoresist type. Surface roughness, a critical parameter in applications such as optics and microfluidics, for example, is also used to determine threshold writing speed. The utility of the approach is demonstrated by making a cell phone keypad light guide from a microreplication tool fabricated using the highly photosensitive photoresist.
Spatial-frequency transfer functions are regularly used to model the imaging performance of near-field �superlens� systems. However, these do not account for interactions between the object that is being imaged and the superlens itself. As the imaging in these systems is in the near field, such interactions are important to consider if accurate performance estimates are to be obtained. We present here a simple analytical modification that can be made to the transfer function to account for near-field interactions for objects consisting of small apertures in otherwise-continuous metal screens. The modified transfer functions are evaluated by comparison with full-field finite-element simulations for representative single-layer and multi-layer silver superlenses, and good agreement is found.
Despite stipulations in the Sudan's 2005 Comprehensive Peace Agreement (CPA) that all ‘other armed groups’ be demobilised by January 2006, the South Sudan Defence Force (SSDF) continued to maintain a significant armed presence in South Sudan. This paper analyses the dynamics of the organisation, the impact of its ongoing presence on the security situation and reconstruction efforts, and attempts by the government of South Sudan to counteract the SSDF from January to August 2006. It argues that the strategies implemented by the government to counter the SSDF were fairly successful in that there was no major return to conflict. However, it concludes that the SSDF's continued presence, while hindered, has the potential to spark a return to civil war.
The Welsh schools that I have seen are generally on the British system … The children in them are generally docile and quick in apprehension, to a greater degree than English children; their drawback, of course, is that they have to acquire the medium of information, as well as the information itself, while the English children possess the medium at the outset. There can, I think, be no question but that the acquirement of the English language should be more and more insisted upon by your Lordships in your relations with these schools as the one main object for which your aid is granted. Whatever encouragement individuals may think it desirable to give the preservation of the Welsh language on grounds of philological or antiquarian interest, it must always be the desire of a Government to render its dominions, as far as possible, homogeneous, and to break down barriers to the freest intercourse between the different parts of them. Sooner or later, the difference of language between Wales and England will probably be effaced, as has happened with the difference of language between Cornwall and the rest of England; as is now happening with the difference of language between Brittany and the rest of France; and they are not the true friends of the Welsh people who, from a romantic interest in their manners and traditions, would impede an event which is socially and politically so desirable for them.
In August 2001, a cluster of MRSA skin infections was detected in a correctional facility. An investigation was conducted to determine its cause and to prevent further MRSA infections.
A 200-bed detention center.
A case was defined as a detainee with a skin lesion from which MRSA was cultured from July 24 through December 31, 2001. Case-patients were identified by review of laboratory culture results and by skin lesion screening through point-prevalence survey and admission examination. Controls were randomly selected from an alphabetized list of detainees.
Medical staff implemented measures to improve skin disease screening, personal hygiene, wound care, and antimicrobial therapy.
Sixteen cases were identified: 11, 5, and 0 in the preintervention, peri-intervention, and postintervention periods, respectively. Seven case-patients and 19 controls were included in the case-control study. On multivariable analysis, working as a dormitory orderly (OR, 9.8; CI95, 0.74-638; P= .10) and a stay of longer than 36 days (OR, 6.9; CI95, 0.65-128.2; P = .14) were the strongest predictors for MRSA skin infection. The preintervention, peri-intervention, and postintervention MRSA infection rates were 11.6, 8.8, and 0 per 10,000 detainee-days, respectively. The rate of MRSA skin infections declined significantly between both the preintervention and peri-intervention periods and the postintervention period (P < .01 for both comparisons).
MRSA skin disease can become an emergent problem in a correctional facility. Interventions targeted at skin disease screening, appropriate antimicrobial treatment, and hygiene may decrease the risk of acquiring MRSA infection in correctional facilities.
Many fossil assemblages are time-averaged, with multiple generations of organisms mixed into a single stratigraphic horizon. A time-averaged sample of a taxon should be more variable than a single-generation sample if enough morphologic change occurred during the interval of time-averaging. Time-averaging may also alter correlations between morphologic variables and obscure allometric relationships in an evolving population. To investigate these issues, we estimated the variability of six modern, single-generation samples of the bivalve Mercenaria campechiensis using Procrustes analysis and compared them with several time-averaged Pleistocene samples of M. campechiensis and M. permagna. Both the modern and the fossil samples ranged in variability, but these ranges were virtually identical. Morphology was quite stable over the hundreds to many thousands of years that passed as the assemblages accumulated, and the variabilities of the fossil samples could be used to estimate single-generation variability. At one fossil locality, the environment and paleocommunity changed partway through the collection interval; the morphology of Mercenaria appears stable above and below the transition but changes across it. This change is similar in magnitude to the differences between geographically separated modern populations, whereas temporal variation within single environmental settings is distinctly less than geographic variation. Analytical time-averaging (the mixing of fossils from different horizons) between paleocommunities increased variability slightly (but not significantly) above that found in living populations. While its constituent populations appear stable on millennial timescales, M. campechiensis has been evolutionarily static since at least the early to middle Pleistocene.
The purpose of the present experiments was to evaluate
the contribution of the glutamate-glutamine cycle in retinal
glial (Müller) cells to photoreceptor cell synaptic
transmission. Dark-adapted isolated rat retinas were superfused
with oxygenated bicarbonate-buffered media. Recordings
were made of the b-wave of the electroretinogram
as a measure of light-induced photoreceptor to ON-bipolar
neuron transmission. L-methionine sulfoximine (1–10
mM) was added to superfusion media to inhibit glutamine
synthetase, a Müller cell specific enzyme, by more
than 99% within 5–10 min, thereby disrupting the
conversion of glutamate to glutamine in the Müller
cells. Threo-hydroxyaspartic acid and D-aspartate were
used to block glutamate transporters. The amplitude of
the b-wave was well maintained for 1–2 h
provided 0.25 mM glutamate or 0.25 mM glutamine was included
in the media. Without exogenous glutamate or glutamine
the amplitude of the b-wave declined by about
70% within 1 h. Inhibition of glutamate transporters led
to a rapid (2–5 min) reversible loss of the b-wave
in the presence and absence of the amino acids. In contrast,
inhibition of glutamine synthetase did not alter significantly
either the amplitude of the b-wave in the presence
of glutamate or glutamine or the rate of decline of the
b-wave found in the absence of these amino acids.
Excellent recovery of the b-wave was found when
0.25 mM glutamate was resupplied to L-methionine sulfoximine–treated
retinas. The results suggest that in the isolated rat retina
uptake of released glutamate into photoreceptors plays
a more important role in transmitter recycling than does
uptake of glutamate into Müller cells and its subsequent
conversion to glutamine.