6,209 research outputs found
No drain, autologous transfusion drain or suction drain? A randomised prospective study in total hip replacement surgery of 168 patients
We performed a prospective, randomised controlled trial to assess the differences in the use of a conventional suction drain, an Autologous Blood Transfusion (ABT) drain and no drain, in 168 patients. There was no significant difference between the drainage from ABT drains ( mean : 345 ml) and the suction drain (314 ml). Forty percent of patients receiving a suction drain had a haemoglobin level less than 10 g/dL at 24 hours, compared to 35% with no drain and 28% with an ABT drain. Patients that had no drains had wounds that were dry significantly sooner, mean 3.0 days compared to a mean of 3.9 days with an ABT drain and a mean of 4 days with a suction drain. Patients that did not have a drain inserted stayed in hospital a significantly shorter period of time, compared with drains. We feel the benefits of quicker drying wounds, shorter hospital stays and the economic savings justify the conclusion that no drain is required after hip replacement
Determinants of Rolling Stock Maintenance Cost in Metros
This study examines the economies of scale and the determinants of rolling stock maintenance costs for 24 urban rail transit operators. The estimates reveal significant returns to scale in maintenance for both per car and per car kilometre. The econometric analysis also provides statistically significant cost elasticities for wages and staff hours, suggesting substitution effects between factors. Staff outsourcing is found to significantly decrease costs, whereas higher levels of fleet availability at the peak and rolling stock failures increase it. The effect of the age of rolling stock and the network is negligible on rolling stock maintenance costs; however, the analysis reveals a downward trend in rolling stock costs among the metros in the CoMET and Nova consortia
Impacts of Unattended Train Operations (UTO) on Productivity and Efficiency in Metropolitan Railways
Urban metro subway systems (metros) around the world are choosing increasing levels of automation for new and existing lines: the global length of metro lines capable of unattended train operation (UTO) is predicted to triple in the next 10 years. Despite significant investment in this technology, empirical evidence for the financial and service quality impacts of UTO in metros remains scarce. This study used questionnaires and semistructured interviews with the Community of Metros and Nova Group benchmarking groups to assemble emerging evidence of how automation affected costs, staffing, service capacity, and reliability. The results from an analysis of data from 23 lines suggested that UTO could reduce staff numbers by 30% to 70%, with the amount of wage cost reduction depending on whether staff on UTO lines were paid more. On the basis of the experience of seven metros, the capital costs of lines capable of UTO were higher, but the internal rate of return had been estimated by two metros at 10% to 15%. Automated lines were capable of operating at the highest service frequencies of up to 42 trains per hour, and the limited available data suggested that automated lines were more reliable. The findings indicated that UTO was a means to a more flexible and reliable operating model that could increase metro productivity and efficiency. The study identified important work needed to understand the impacts of UTO and identify where statistical analyses would add value once sufficiently large data sets became available
High resolution satellite observations give new view of UK air quality
New stateâofâtheâart satellite measurements of tropospheric column NO2 from the TROPOMI instrument onâboard Sentinelâ5 Precursor (S5P), launched in October 2017, allow for an unprecedented high resolution (subâ10km) assessment of UK air quality (AQ) from space. We present the first results from TROPOMI and compare them with its predecessor, the Ozone Monitoring Instrument (OMI), to quantify previously unresolved UK pollution hotspots (e.g. Bristol, Southampton and Liverpool). The TROPOMI tropospheric column NO2 data represents a powerful new tool to quantify UK AQ, evaluate atmospheric composition models and potentially derive new emission inventories from space
High resolution satellite observations give new view of UK air quality
New stateâofâtheâart satellite measurements of tropospheric column NO2 from the TROPOMI instrument onâboard Sentinelâ5 Precursor (S5P), launched in October 2017, allow for an unprecedented high resolution (subâ10km) assessment of UK air quality (AQ) from space. We present the first results from TROPOMI and compare them with its predecessor, the Ozone Monitoring Instrument (OMI), to quantify previously unresolved UK pollution hotspots (e.g. Bristol, Southampton and Liverpool). The TROPOMI tropospheric column NO2 data represents a powerful new tool to quantify UK AQ, evaluate atmospheric composition models and potentially derive new emission inventories from space
Quantifying the transboundary contribution of nitrogen oxides to UK air quality
Nitrogen dioxide (NO2) pollution is an important contributor to poor air quality (AQ) and a significant cause of premature deaths in the UK. Although transboundary (i.e., international) transport of pollution to the UK is believed to have an impact on UK pollutant concentrations, large uncertainties remain in these estimates. Therefore, the extent to which emission reductions in neighbouring countries would benefit UK AQ relative to local emission reductions also remains unknown. We have used a backâtrajectory model in conjunction with synoptic scale classifications of UK circulation patterns (Lamb Weather Types [LWT]), to quantify the accumulation of nitrogen oxide (NO x = NO2â+âNO) emissions in air masses enâroute to the UK. This novel method presents a computationally inexpensive and useful method of quantifying the accumulation of pollutants under different circulation patterns. We find the highest accumulated NO x totals occur under southâeasterly and southerly flows (>15âÎŒgâ
mâ2), with a substantial contribution from outwith the UK (>25%). In contrast, the total accumulated NO x under northerly and westerly flows is lower (âŒ10 ÎŒgâ
mâ2), and dominated by UK emissions (>95%). This indicates that European emissions can contribute substantially to UK localâscale pollution in urban areas under southâeasterly and southerly flows. The sensitivity of integrated NO x emission totals under different air masses is investigated by modelling future European emission contributions based on emission reduction targets. Under targets set by the European Union, there would be a decrease in accumulated NO x emissions in London under most wind directions except for northâwesterly, westerly and northerly flow. The largest benefits to UK AQ from transboundary contributions occur with emission reductions in the Benelux region, due to its close proximity and high NO x emission rates, emphasising the importance of international cooperation in improving local AQ
Pioneers in CNS inhibition: 2. Charles Sherrington and John Eccles on inhibition in spinal and supraspinal structures
This article reviews the contributions of the English neurophysiologist, Charles Scott Sherrington [1857â1952], and his Australian PhD trainee and collaborator, John Carew Eccles [1903â1997], to the concept of central inhibition in the spinal cord and brain. Both were awarded Nobel Prizes; Sherrington in 1932 for âdiscoveries regarding the function of neurons,â and Eccles in 1963 for âdiscoveries concerning the ionic mechanisms involved in excitation and inhibition in central portions of the nerve cell membrane.â Both spoke about central inhibition at their Nobel Prize Award Ceremonies. The subsequent publications of their talks were entitled âInhibition as a coordinative factorâ and âThe ionic mechanism of postsynaptic inhibitionâ, respectively. Sherrington's work on central inhibition spanned 41âŻyears (1893â1934), and for Eccles 49âŻyears (1928â1977). Sherrington first studied central inhibition by observing hind limb muscle responses to electrical (peripheral nerve) and mechanical (muscle) stimulation. He used muscle length and force measurements until the early 1900s and electromyography in the late 1920s. Eccles used these techniques while working with Sherrington, but later employed extracellular microelectrode recording in the spinal cord followed in 1951 by intracellular recording from spinal motoneurons. This considerably advanced our understanding of central inhibition. Sherrington's health was poor during his retirement years but he nonetheless made a small number of largely humanities contributions up to 1951, one year before his death at the age of 94. In contrast, Eccles retained his health and vigor until 3âŻyears before his death and published prolifically on many subjects during his 22âŻyears of official retirement. His last neuroscience article appeared in 1994 when he was 91. Despite poor health he continued thinking about his life-long interest, the mind-brain problem, and was attempting to complete his autobiography in the last years of his life
Restrictive covenants in Xanadu
Legal scholarship is naturally inclined towards explanations and justifications of contemporary law. In the case of restrictive covenants and building schemes this has led to a distorted perception of the historical record, as revealed in recorded case reports dating from the nineteenth century. It is argued that the restrictive covenant had its historical genesis not in a response to industrialisation and mass urbanisation, but in the developments of resort towns in the eighteenth and early nineteenth centuries, as a response to the needs of land developers. Furthermore, it is argued that a better historical understanding of these origins illuminates contemporary problems concerned with the adaptability of law and the potential roles of law in development
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