40 research outputs found
Seasonal speedup of a Greenland marine-terminating outlet glacier forced by surface melt-induced changes in subglacial hydrology
We present subdaily ice flow measurements at four GPS sites between 36 and 72 km from the margin of a marine-terminating Greenland outlet glacier spanning the 2009 melt season. Our data show that >35 km from the margin, seasonal and shorter–time scale ice flow variations are controlled by surface melt–induced changes in subglacial hydrology. Following the onset of melting at each site, ice motion increased above background for up to 2 months with resultant up-glacier migration of both the onset and peak of acceleration. Later in our survey, ice flow at all sites decreased to below background. Multiple 1 to 15 day speedups increased ice motion by up to 40% above background. These events were typically accompanied by uplift and coincided with enhanced surface melt or lake drainage. Our results indicate that the subglacial drainage system evolved through the season with efficient drainage extending to at least 48 km inland during the melt season. While we can explain our observations with reference to evolution of the glacier drainage system, the net effect of the summer speed variations on annual motion is small (∼1%). This, in part, is because the speedups are compensated for by slowdowns beneath background associated with the establishment of an efficient subglacial drainage system. In addition, the speedups are less pronounced in comparison to land-terminating systems. Our results reveal similarities between the inland ice flow response of Greenland marine- and land-terminating outlet glaciers
Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial
Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome
Recherche aux possibilities de conditionnement des boeufs de labour a base de paille de brousse enrichie a l'uree et evaluation de son impact sur leur capacite de travail
Recherche aux effets de poids vif et emponpoint des boeufs de labour sur la capacite de travail
Effect of liveweight and body condition on work output from draft oxen
A trial was carried out to assess the effect of liveweight and body condition on working capacity of Zebu oxen. Over a working period of 9 days, animals which started work with a mean liveweight of 360 kg and body condition score of M+ produced the highest daily work output. At an initial liveweight of 360 kg, body condition had relatively little effect on work output of 3.19 MJ. In contrast, at a mean live-weight of 310 kg. at the start of work, mean daily work output of animals of condition score M+ was significantly lower than that of animals in poorer condition (M-) at 0.81 compared with 2.50 MJ work output per day. It was concluded that body weight as indicated by body size is probably a more useful indicator of likely capacity for work than body condition under the short-season working conditions typical for oxen in the semi-arid zone of central Mali
In-village studies of the use of work oxen in central Mali
Amongst 186 farmers interviewed in 1986 in central Mali 95 percent declared having used oxen for at least some part of their crop production activities. Most of the users (98 percent) had exploited oxen for soil preparation, but only 66 percent had used animal-drawn equipment for weeding. Only 21 percent of respondents attributed problems with field operations to deficiency in oxen work-capacity. On average oxen undertook 22 days of primary cultivation and 11 days of weeding in 1989. All the work observed was carried out using oxen harnessed in pairs. Soil preparation consisted principally of ridging with a single-furrow plough (16 days work) and this was carried out at an average working speed of 0.75 m.s.-1 with an average draft force of 778 N. Inter-row weeding was generally made with a duck-foot harrow working at 0.77 m.s.-1 at an average draft force of 610 N. The average work load in primary cultivations was 138 N. 100 kg-1 liveweight and for weeding 120 N. 100 kg-1 liveweight. Liveweight and size of oxen had no evident effect on working performance. Energy consumption in work was estimated at 144 percent and 136 percent of maintenance requirement for primary cultivation and weeding respectively
Effect of change in body weight and condition during the dry season on capacity for work of draft oxen
Work oxen supplemented at different levels during a feeding period of 3 months, were divided into 3 groups of average weight change -25, +35 and +70kg and worked under loadings of either 7.5 or 12.5 kgf/100kg of liveweight for 2 weeks, in order to assess the impact of dry season supplementation on capacity for work. At approximately equal levels of stress in work, manifest in maximum heart rate one minute after ceasing work, oxen with higher dry-season weight gain produced higher levels of work output, in proportion to their increased body weight. Rate of work and mean daily work output increased from the first to the second week of work, inspite of average daily weight losses of 2.63 kg throughout the period. Decline in rate of working through each day was continuous and essentially linear with relation to distance worked. The time taken to cover 1km increased at an average of 0.16 and 0.68 min/km for light and heavy loadings respectively
Potential of natural pasture and locally available supplements in ruminant nutrition in semi-arid location in West Africa
Discusses the potential of natural pasture and locally available supplements in ruminant nutrition in a semi-arid location in west Africa. Presents data on protein and energy concentration of pasture, on crude nutrients and on energy content of supplement, on nutritive contents of pastures in dry season, and on average body composition of two experimental cattle groups in 1989. Recovery rates and reproducibility of experiments were tested under varying conditions to evaluate polyamide granula as an external marker. Various adaptation periods and possible sources of error in recovering markers were tested. In addition, 2 different methods for obtaining samples were tested under controlled and field conditions
Effects of supplementation of molassed natural pasture hay with urea, and of water intake restriction on feed intakes by Zebu cattle in the semi-arid zone of Mali
The effects on intake of water availability and urea addition to rations based on molassed natural pasture hay and dry cowpea haulm were measured using 6 mature castrated male Zebu cattle of 343 kg mean iveweight, in an experiment carried out during the dry season in the semi-arid zone of central Mali. The trial was executed and analysed in in which each animal was subject to each of 6 treatments, successively over 6 feeding periods, each of 10 days' duration, throughout which the animals were tied in stalls under shade and fed and watered individually. Natural pasture hay comprising predominantly Pennisetum pedicellatum was fed ad libitum in mixture with 40 percent molasses, with and without addition of urea. Cowpea haulm was fed as a supplement to both diets. Feeding treatments were combined factorially with levels of water allowance. The limited impact of water restriction on feed intake suggests that shortage of drinking water may have a smaller effect on productivity of housed livestock than has been feared, and is an effect which may be compensated for, in the short-term at least by an increase in diet quality