29 research outputs found
Cardiopulmonary exercise testing for the evaluation of perioperative risk in non-cardiopulmonary surgery
No full textThe use of cardiopulmonary exercise testing (CPET) as a preoperative risk stratification tool for a range of non-cardiopulmonary surgery is increasing. The utility of CPET in this role is dependent on the technology being able to identify accurately and reliably those patients at increased risk of perioperative events when compared with existing risk stratification tools. This article identifies and reviews systematically the current literature regarding the use of CPET as a preoperative tool for stratifying risk in major non-cardiopulmonary surgery. Specifically, it focuses on evaluating the capacity of CPET variables to predict the risk of postoperative complications and mortality in comparison to other methods of risk assessment. Furthermore, the potential for combining results from CPET and non-CPET methods of risk prediction to enhance the capacity to identify high risk patients is considered. The review indicates that CPET can identify patients at increased risk of adverse perioperative outcomes. However, the selection of variables and threshold values to indicate high risk differ for different surgical procedures and underlying conditions. Furthermore, the available data suggest that CPET variables outperform alternative methods of preoperative risk stratification. Several studies also identify that CPET variables may be used in combination with non-CPET variables to increase perioperative risk prediction accuracy. These findings illustrate that CPET has the capacity to identify patients at increased risk of adverse outcome before a range of non-cardiopulmonary surgical procedures. Further research is required to optimise its use, potentially by combining CPET results with alternative methods of risk stratification
Sustained vasomotor control of skin microcirculation in Sherpas versus altitude-naive lowlanders: Experimental evidence from Xtreme Everest 2
No full textEnhanced oxygen delivery, consequent to an increased microvascular perfusion, has been postulated to play a key role in the physiological adaptation of Tibetan highlanders to the hypobaric hypoxia encountered at high altitude. We tested the hypothesis that Sherpas, when exposed to graded hypobaric hypoxia, demonstrate enhanced vasomotor and neurovascular control to maintain microcirculatory flux, and thus tissue oxygenation, when compared with altitude‐naive lowlanders. Eighty‐three lowlanders [39 men and 44 women, 38.8 (13.1) years old; mean (SD)] and 61 Sherpas [28 men and 33 women, 27.9 (6.9) years old] were studied on ascent to Everest Base Camp over 11 days. Skin blood flux and tissue oxygen saturation were measured simultaneously using combined laser Doppler fluximetry and white light spectroscopy at baseline, 3500 and 5300 m. In both cohorts, ascent resulted in a decline in the sympathetically mediated microvascular constrictor response (P < 0.001), which was more marked in lowlanders than in Sherpas (P < 0.001). The microvascular dilator response evaluated by postocclusive reactive hyperaemia was significantly greater in Sherpas than in lowlanders at all sites (P < 0.002). Spectral analysis of the blood flux signals revealed enhanced myogenic (vasomotion) activity in Sherpas, which was unaffected by ascent to 5300 m. Although skin tissue oxygenation was lower in Sherpas than in lowlanders, the oxygen unloading rate was faster, and deoxyhaemoglobin levels higher, at all altitudes. Together, these data suggest that Sherpas, when exposed to hypobaric hypoxia, demonstrated superior preservation of peripheral microcirculatory perfusion compared with altitude‐naive lowlanders. The physiological differences in local microvasculature vasomotor and neurovascular control may play a key role in Sherpa adaptation to high‐altitude hypobaric hypoxia by sustaining local perfusion and tissue oxygenation
Engaging the manuscript: new editions and reading the 'whole book' in Chetham's Library MS 8009
No full textThis thesis considers the intersection of the manuscript and its literature through an examination of the late fifteenth century manuscript, Chetham’s Library 8009 (Mun. A.6.31) and provides four diplomatic editions. This manuscript contains fourteen texts in Middle English including romance, hagiography, courtesy literature, and a comic text. This thesis argues for the importance of reading medieval literature in its manuscript context. Although there is a growing trend to consider the ‘whole book’ and integrate analysis of the material artefact with interpretation, much work remains to be done.
In Part I, this thesis presents a new paradigm for reading medieval literature, and argues that the manuscript forms a very literal community of texts, and that each text acts as a co-creator of meaning with the others. It then demonstrates four brief contextual readings that may be made within Chetham 8009 across generic boundaries, and that produce a shift in interpretive focus .
Part II provides four diplomatic editions from Chetham 8009: the Life of St Katherine, the Liber Catonis, John Russell’s Book of Carving and Nurture, and the Book of the Duke and Emperor.
This thesis aims to contribute to the study of medieval literature by arguing for a methodological shift in the way the literature is approached and by providing access to four texts either previously unedited or not easily accessible
Cardiopulmonary exercise testing predicts postoperative outcome in patients undergoing gastric bypass surgery
No full textAT, determined using CPET, predicts LOS after gastric bypass surgery
Design and conduct of 'Xtreme Alps' : a double-blind, randomised controlled study of the effects of dietary nitrate supplementation on acclimatisation to high altitude
No full textThe study of healthy human volunteers ascending to high altitude provides a robust model of the complex physiological interplay that emulates human adaptation to hypoxaemia in clinical conditions. Nitric oxide (NO) metabolism may play an important role in both adaptation to high altitude and response to hypoxaemia during critical illness at sea level. Circulating nitrate and nitrite concentrations can be augmented by dietary supplementation and this is associated with improved exercise performance and mitochondrial efficiency. We hypothesised that the administration of a dietary substance (beetroot juice) rich in nitrate would improve oxygen efficiency during exercise at high altitude by enhancing tissue microcirculatory blood flow and oxygenation. Furthermore, nitrate supplementation would lead to measurable increases in NO bioactivity throughout the body.
This methodological manuscript describes the design and conduct of the ‘Xtreme Alps’ expedition, a double-blind randomised controlled trial investigating the effects of dietary nitrate supplementation on acclimatisation to hypobaric hypoxia at high altitude in healthy human volunteers. The primary outcome measure was the change in oxygen efficiency during exercise at high altitude between participants allocated to receive nitrate supplementation and those receiving a placebo. A number of secondary measures were recorded, including exercise capacity, peripheral and microcirculatory blood flow and tissue oxygenation.
Results from this study will further elucidate the role of NO in adaption to hypoxaemia and guide clinical trials in critically ill patients. Improved understanding of hypoxaemia in critical illness may provide new therapeutic avenues for interventions that will improve survival in critically ill patients
Effect of dietary nitrate on respiratory physiology at high altitude - results from the Xtreme Alps study
No full textNitric oxide (NO) production plays a central role in conferring tolerance to hypoxia. Tibetan highlanders, successful high-altitude dwellers for millennia, have higher circulating nitrate and exhaled NO (ENO) levels than native lowlanders. Since nitrate itself can reduce the oxygen cost of exercise in normoxia it may confer additional benefits at high altitude. Xtreme Alps was a double-blinded randomised placebo-controlled trial to investigate how dietary nitrate supplementation affects physiological responses to hypoxia in 28 healthy adult volunteers resident at 4559m for 1 week; 14 receiving a beetroot-based high-nitrate supplement and 14 receiving a low-nitrate ‘placebo’ of matching appearance/taste. ENO, vital signs and acute mountain sickness (AMS) severity were recorded at sea level (SL) and daily at altitude. Moreover, standard spirometric values were recorded, and saliva and exhaled breath condensate (EBC) collected. There was no significant difference in resting cardiorespiratory variables, peripheral oxygen saturation or AMS score with nitrate supplementation at SL or altitude. Median ENO levels increased from 1.5/3.0mPa at SL, to 3.5/7.4mPa after 5 days at altitude (D5) in the low and high-nitrate groups, respectively (p=0.02). EBC nitrite also rose significantly with dietary nitrate (p=0.004), 1.7 to 5.1μM at SL and 1.6 to 6.3 μM at D5, and this rise appeared to be associated with increased levels of ENO. However no significant changes occurred to levels of EBC nitrate or nitrosation products (RXNO). Median salivary nitrite/nitrate concentrations increased from 56.5/786µM to 333/5,194µM at SL, to 85.6/641µM and 341/4,553µM on D5. Salivary RXNO rose markedly with treatment at SL from 0.55µM to 5.70µM. At D5 placebo salivary RXNO had increased to 1.90µM whilst treatment RXNO decreased to 3.26µM. There was no association with changes in any observation variables or AMS score. In conclusion, dietary nitrate supplementation is well tolerated at altitude and significantly increases pulmonary NO availability and both salivary and EBC NO metabolite concentrations. Surprisingly, this is not associated with changes in hemodynamics, oxygen saturation or AMS development
"Thank me therefore": Social Prestige, Probity and Self-determination of Nymue's character in Malory's "Le Morte Darthur"
No full textKur’an’ın Kürtçe çevirilerinde karşılaşılan problemler “Meale Firuz Şerha Qur’ana Piroz” örneği
No full textBu çalışmanın amacı, “Meala Fîrûz ?erha Qur?ana Pîroz” adlı Kur?an?ın Kürtçe mealinde karşılaşılan genel çeviri sorunlarını, eksik veya yanlış meal örneklerini etraflı bir şekilde ele alarak değerlendirmektir. Temel olarak bu çalışma, giriş ve sonuç dışında iki bölümden olu?maktadır. “Kürtçe Tefsir ve Meal Gelişim Süreci” başlıklı ilk bölümde, Irak, İran ve Türkiye?de yapılan Kur?an?ın Kürtçe tefsir-meal çalışmalarına ve müelliflerinin hayatlarına değinilmektedir. İkinci bölümde ise, yazarın hayatı ve mealin biçimsel ve dilsel tahlilinin yanı sıra, mealde sıkça karşılaşılan harfî tercüme sorununa, sözcük ve âyet düzeyinde yapılan yanlış veya eksik tercümelere, Kürtçe anlatım biçimine uygun düşmeyen veya anlamı belirsiz meal örneklerine, zıt iki anlamı birlikte verme ve parantez problemlerine değinilmektedir. Sonuçta ise, çalışma neticesinde ulaşılan tespitlere yer verilmektedir. Anahtar Sözcükler Kürtçe meal, çeviri sorunları, harfî çeviri problemi, Meala Fîrûz, Qur?ana PîrozThe goal of our thesis is to examine general translation problems and incomplete or wrong translation examples comprehensively in the Quran Translation named “Meala Fîrûz ?erha Qur?ana Pîroz.” The thesis has two chapters aside from introduction and conclusion. In the first chapter named “the process of the development of Kurdish interpretation and translation activities” the works of interpretation-translation in Iraq, Iran and Turkey, and the biographies of authors are mentioned. In the second chapter, the life of the author, and formal and linguistic analysis of the text as well as problem of literal translation problems encountered frequently in the text, wrong or incomplete translation at the levels of word and verses, translation examples which do not comply with Kurdish phraseology or ambiguous translations, signifying opposite meanings, and parenthesis problems are dealt with. In the conclusion chapter the results obtained at the end of the study are examined. Key Words Kurdish translation, translation problems, literal translation, Meala Fîrûz, Qur?ana Pîro
Saccharomyces cerevisiae fermentation products (SCFP) stabilize the ruminal microbiota of lactating dairy cows during periods of a depressed rumen pH
No full textBackground: Effects of Saccharomyces cerevisiae fermentation products (SCFP) on rumen microbiota were determined in vitro and in vivo under a high and a depressed pH. The in vitro trial determined the effects of Original XPC and NutriTek (Diamond V, Cedar Rapids, IA) at doses of 1.67 and 2.33 g/L, respectively, on the abundances of rumen bacteria under a high pH (> 6.3) and a depressed pH (5.8-6.0) using quantitative PCR (qPCR). In the in vivo trial eight rumen-cannulated lactating dairy cows were used in a cross-over design. Cows were randomly assigned to SCFP treatments (Original XPC, Diamond V, Cedar Rapids, IA) or control (No SCFP) before two 5-week experimental periods. During the second period, SCFP treatments were reversed. Cows on the SCFP treatment were supplemented with 14 g/d of SCFP and 126 g/d of ground corn. Other cows received 140 g/d ground corn. During the first 4 wk. of each period, cows received a basal diet containing 153 g/kg of starch. During week 5 of both periods, the rumen pH was depressed by a SARA challenge. This included replacing 208 g/kg of the basal diet with pellets of ground wheat and barley, resulting in a diet that contained 222 g/kg DM of starch. Microbial communities in rumen liquid digesta were examined by pyrosequencing, qPCR, and shotgun metagenomics. Results: During the in vitro experiment, XPC and NutriTek increased the relative abundances of Ruminococcus flavefaciens, and Fibrobacter succinogenes determined at both the high and the depressed pH, with NutriTek having the largest effect. The relative abundances of Prevotella brevis, R. flavefaciens, ciliate protozoa, and Bifidobacterium spp. were increased by XPC in vivo. Adverse impacts of the in vivo SARA challenge included reductions of the richness and diversity of the rumen microbial community, the abundances of Bacteroidetes and ciliate protozoa in the rumen as determined by pyrosequencing, and the predicted functionality of rumen microbiota as determined by shotgun metagenomics. These reductions were attenuated by XPC supplementation. Conclusions: The negative effects of grain-based SARA challenges on the composition and predicted functionality of rumen microbiota are attenuated by supplementation with SCFP
Dietary Nitrate Supplementation Does Not Alter Exercise Efficiency at High Altitude – Further Results From the Xtreme Alps Study
No full textIntroduction: Nitrate supplementation in the form of beetroot juice (BRJ) ingestion has been shown to improve exercise tolerance during acute hypoxia, but its effect on exercise physiology remains unstudied during sustained terrestrial high altitude exposure. We hypothesised that performing exercise at high altitude would lower circulating nitrate and nitrite levels and that BRJ ingestion would reverse this phenomenon while concomitantly improving key determinants of aerobic exercise performance. Methods: Twenty seven healthy volunteers (21 male) underwent a series of exercise tests at sea level (SL, London, 75 m) and again after 5-8 days at high altitude (HA, Capanna Regina Margherita or ‘Margherita Hut’, 4559 m). Using a double-blind protocol, participants were randomised to consume a beetroot/fruit juice beverage (3 doses per day) with high levels of nitrate (~0.18 mmol/kg/day) or a nitrate-depleted placebo (~11.5 μmoles/kg/day) control drink, from 3 days prior to the exercise trials until completion. Submaximal constant work rate cycle tests were performed to determine exercise efficiency and a maximal incremental ramp exercise test was undertaken to measure aerobic capacity, using breath-by-breath pulmonary gas exchange measurements throughout. Concentrations of nitrate, nitrite and nitrosation products were quantified in plasma samples collected at 5 timepoints during the constant work rate tests. Linear mixed modelling was used to analyse data.Results: At both SL & HA, plasma nitrate concentrations were elevated in the nitrate supplementation group compared to placebo (P<0.001) but did not change throughout increasing exercise work rate. Delta exercise efficiency was not altered by altitude exposure (P=0.072) or nitrate supplementation (P=0.836). \.VO2peak decreased by 24 at high altitude (P<0.001) and was lower in the nitrate-supplemented group at both sea level and high altitude compared to placebo (P=0.041). Dietary nitrate supplementation did not alter other peak exercise variables or oxygen consumption at anaerobic threshold. Circulating nitrite and S-nitrosothiol levels unexpectedly rose in a few individuals right after cessation of exercise at high altitude.Conclusion: Whilst regularly consumed during an 8 day expedition to terrestrial high altitude, nitrate supplementation did not alter exercise efficiency and other exercise physiological variables, except decreasing \.VO2peak. These results and those of others question the practical utility of BRJ consumption during prolonged altitude exposure
