985 resultados para TIDAL VOLUME


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The gametogenic and spat settlement patterns of two Mytihis edulis beds were studied in Dundrum Inner Bay, Northern Ireland. There was evidence of gonad development throughout the year with the main development period between November and March. Spawning was protracted, lasting from May to November. Slight inter-annual and inter-population differences in the riming of the phases were observed but the cycles at both beds were broadly similar to each other and to those of other British and Irish sites. Settlement occurred throughout the year and there was evidence of both primary and secondary spat settlement at both sites. Although the reproductive cycles were similar, distinct seasonal and inter-site differences in spatfall were apparent. At the Downshire Bridge bed, settlement peaked during summer and was dominated by spat in the 0•;5-1•0 mm size range. At Ballykinler, settlement levels were highest in the winter months and larger (>1 mm) spat dominated the samples. The orientation of spat collection pads also significantly affected numbers of the larger (>1 mm) spat. Collectors facing the flood tide attracted significantly more secondary settlers than ebb-facing collectors. This effect varied seasonally and was greater at the Ballykinler bed. It is suggested that hydrodynamic regimes may be an important factor in the differences in settlement patterns of M. edulis.

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This edition of Milton’s Epistolarum Familiarium Liber Unus and of his Uncollected Letters, will appear as 672 pp. of The Complete Works of John Milton Volume XI, eds. Gordon Campbell and Edward Jones (Oxford University Press, forthcoming 2016). A diplomatic Latin text and a new facing English translation are complemented by a detailed Introduction and commentary that situate Milton’s Latin letters in relation to the classical, pedagogical and essentially humanist contexts at the heart of their composition. Now the art of epistolography advocated and exemplified by Cicero and Quintilian and embraced by Renaissance pedagogical manuals is read through a humanist filter whereby, via the precedent (and very title) of Epistolae Familiares, the Miltonic Liber is shown to engage with a neo-Latin re-invention of the classical epistola that had come to birth in quattrocento Italy in the letters of Petrarch and his contemporaries. At the same time the Epistolae are seen as offering fresh insight into Milton’s views on education, philology, his relations with Italian literati, his blindness, the poetic dimension of his Latin prose, and especially his verbal ingenuity as the ‘words’ of Latin ‘Letters’ become a self-conscious showcasing of etymological punning on the ‘letters’ of Latin ‘words’. The edition also announces several new discoveries, most notably its uncovering and collation of a manuscript of Henry Oldenburg’s transcription (in his Liber Epistolaris held in Royal Society, London) of Milton’s Ep. Fam. 25 (to Richard Jones). Oldenburg’s transcription (from the original sent to his pupil Jones) is an important find, given the loss of all but two of the manuscripts of Milton’s original Latin letters included in the 1674 volume. The edition also presents new evidence in regard to Milton’s relationships with the Italian philologist Benedetto Buonmattei, the Greek humanist Leonard Philaras, the radical pastor Jean Labadie (and the French church of London), and the elusive Peter Heimbach.

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BACKGROUND: Acute ankle sprains are usually managed functionally, with advice to undertake progressive weight-bearing and walking. Mechanical loading is an important modular of tissue repair; therefore, the clinical effectiveness of walking after ankle sprain may be dose dependent. The intensity, magnitude and duration of load associated with current functional treatments for ankle sprain are unclear.

AIM: To describe physical activity (PA) in the first week after ankle sprain and to compare results with a healthy control group.

METHODS: Participants (16-65 years) with an acute ankle sprain were randomised into two groups (standard or exercise). Both groups were advised to apply ice and compression, and walk within the limits of pain. The exercise group undertook additional therapeutic exercises. PA was measured using an activPAL accelerometer, worn for 7 days after injury. Comparisons were made with a non-injured control group.

RESULTS: The standard group were significantly less active (1.2 ± 0.4 h activity/day; 5621 ± 2294 steps/day) than the exercise (1.7 ± 0 .7 h/day, p=0.04; 7886 ± 3075 steps/day, p=0.03) and non-injured control groups (1.7 ± 0.4 h/day, p=0.02; 8844 ± 2185 steps/day, p=0.002). Also, compared with the non-injured control group, the standard and exercise groups spent less time in moderate (38.3 ± 12.7 min/day vs 14.5 ± 11.4 min/day, p=0.001 and 22.5 ± 15.9 min/day, p=0.003) and high-intensity activity (4.1 ± 6.9 min/day vs 0.1 ± 0.1 min/day, p=0.001 and 0.62 ± 1.0 min/day p=0.005).

CONCLUSION: PA patterns are reduced in the first week after ankle sprain, which is partly ameliorated with addition of therapeutic exercises. This study represents the first step towards developing evidence-based walking prescription after acute ankle sprain.

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Although it is well known that sandstone porosity and permeability are controlled by a range of parameters such as grain size and sorting, amount, type, and location of diagenetic cements, extent and type of compaction, and the generation of intergranular and intragranular secondary porosity, it is less constrained how these controlling parameters link up in rock volumes (within and between beds) and how they spatially interact to determine porosity and permeability. To address these unknowns, this study examined Triassic fluvial sandstone outcrops from the UK using field logging, probe permeametry of 200 points, and sampling at 100 points on a gridded rock surface. These field observations were supplemented by laser particle-size analysis, thin-section point-count analysis of primary and diagenetic mineralogy, quantitiative XRD mineral analysis, and SEM/EDAX analysis of all 100 samples. These data were analyzed using global regression, variography, kriging, conditional simulation, and geographically weighted regression to examine the spatial relationships between porosity and permeability and their potential controls. The results of bivariate analysis (global regression) of the entire outcrop dataset indicate only a weak correlation between both permeability porosity and their diagenetic and depositional controls and provide very limited information on the role of primary textural structures such as grain size and sorting. Subdividing the dataset further by bedding unit revealed details of more local controls on porosity and permeability. An alternative geostatistical approach combined with a local modelling technique (geographically weighted regression; GWR) subsequently was used to examine the spatial variability of porosity and permeability and their controls. The use of GWR does not require prior knowledge of divisions between bedding units, but the results from GWR broadly concur with results of regression analysis by bedding unit and provide much greater clarity of how porosity and permeability and their controls vary laterally and vertically. The close relationship between depositional lithofacies in each bed, diagenesis, and permeability, porosity demonstrates that each influences the other, and in turn how understanding of reservoir properties is enhanced by integration of paleoenvironmental reconstruction, stratigraphy, mineralogy, and geostatistics.

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Although histamine release is recognised as a common event during anaesthesia and surgery, few clinicians judge the resultant cardiorespiratory disturbances serious enough to warrant prophylaxis with antihistamines. We have assessed the incidence and importance of histamine release in a randomised 2 x 2 factorial study.

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Measurements of plasma parameters, including H- ion densities, made in conjunction with wall temperature, visible and vacuum ultraviolet emission spectroscopy verify that there is little caesium in the plasma volume of the H- ion source. Surface work function measurements indicate that there is significant caesium coverage of the inner walls of the ion source. It is found that, as the work function of a test surface decreases due to caesium seeding, the H- ion fraction in the discharge volume increases. These observations combine to indicate that, in the present source, the H- ion enhancement mechanism is a surface dominated effect. (C) 1999 American Institute of Physics. [S0003- 6951(99)04744-0].

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In this paper we demonstrate a new concept in the production of negative hydrogen ions in a low-pressure multicusp discharge. The discharge voltage is modulated to produce a non-Maxwellian, hot-electron plasma during the current pulse, followed by a cool Maxwellian electron plasma in the post discharge. This procedure, of separating in time the required hot and cold electron plasmas required for volume H- production, is called a temporal filter. The time evolution of the electron energy distribution function is measured using the time-resolved second derivative of a Langmuir probe characteristic. Time-resolved measurements of the negative ion density are made using laser photodetachment. The measurements show that the negative ion density in the center of the source, at a gas pressure of 0.07 Pa, increases by a factor of 2 when the discharge is switched off. At this low pressure the average H- beam current extracted from the source, when operated with a discharge current of 1 A in the pulse modulated mode exceeds the H- beam current from a 5 A continuously operated source. The increase in efficiency of the pulsed source is explained in terms of a two-step H- production mechanism.