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See detailEvaluating Model Simulations of Twentieth-Century Sea Level Rise. Part 2: Regional Sea-Level Changes
Meyssignac, B.; Slangen, A.; Melet, A. et al

in Journal of Climate (2017), in press

Twentieth century regional sea-level changes are estimated from 12 climate models from the 5th phase of the Climate Model Intercomparison Project (CMIP5). The output of the CMIP5 climate model simulations ... [more ▼]

Twentieth century regional sea-level changes are estimated from 12 climate models from the 5th phase of the Climate Model Intercomparison Project (CMIP5). The output of the CMIP5 climate model simulations were used to calculate the global and regional sea-level changes associated with dynamic sea level, atmospheric loading, glacier mass changes and ice sheet surface mass balance contributions. The contribution from groundwater depletion, reservoir storage and dynamic ice sheet mass changes are estimated from observations as they are not simulated by climate models. All contributions are summed, including the GIA contribution, and compared to observational estimates from 27 tide gauge records over the twentieth century (1900-2015). We find a general agreement between the simulated sea level and tide gauge records in terms of inter-annual to multi-decadal variability over 1900-2015. But climate models tend to systematically underestimate the observed sea-level trends, particularly in the first half of the 20th century. The corrections based on attributable biases between observations and models that have been identified in the part-1-paper, result in an improved explanation of the spatial variability in observed sea-level trends by climate models. Climate models show that the spatial variability in sea-level trends observed by tide-gauge records is dominated by the GIA contribution and the steric contribution over 1900-2015. Climate models also show that it is important to include all contributions to sea-level changes as they cause significant local deviations; for example, the groundwater depletion around India which is responsible for the low 20th century sea-level rise in the region. [less ▲]

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See detailEvaluating model simulations of 20th century sea-level rise. Part 1: Global mean sea-level change
Slangen, A.; Meyssignac, B.; Agosta, Cécile ULiege et al

in Journal of Climate (2017)

Sea-level change is one of the major consequences of climate change and is projected to affect coastal communities around the world. Here, we compare Global Mean Sea-Level (GMSL) change estimated by 12 ... [more ▼]

Sea-level change is one of the major consequences of climate change and is projected to affect coastal communities around the world. Here, we compare Global Mean Sea-Level (GMSL) change estimated by 12 climate models from the 5th phase of the World Climate Research Programme’s Climate Model Intercomparison Project (CMIP5) to observational estimates for the period 1900-2015. We analyse observed and simulated individual contributions to GMSL change (thermal expansion, glacier mass change, ice sheet mass change, landwater storage change) and compare the summed simulated contributions to observed GMSL change over the period 1900-2007 using tide gauge reconstructions, and over the period 1993-2015 using satellite altimetry estimates. The model-simulated contributions allow us to explain 50 ± 30% (uncertainties 1.65σ unless indicated otherwise) of the mean observed change from 1901-1920 to 1988-2007. Based on attributable biases between observations and models, we propose to add a number of corrections, which result in an improved explanation of 75 ± 38% of the observed change. For the satellite era (1993-1997 to 2011-2015) we find an improved budget closure of 102 ± 33% (105 ± 35% when including the proposed bias corrections). Simulated decadal trends over the 20th century increase, both in the thermal expansion and the combined mass contributions (glaciers, ice sheets and landwater storage). The mass components explain the majority of sea-level rise over the 20th century, but the thermal expansion has increasingly contributed to sea-level rise, starting from 1910 onwards and in 2015 accounting for 46% of the total simulated sea-level change. [less ▲]

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See detailRelationship between markers of blood oxidant status and physiological variables in healthy and heaves-affected horses after exercise
Kirschvink, Nathalie; Art, Tatiana ULiege; de Moffarts, Brieuc et al

in Equine Veterinary Journal. Supplement (2002), 34

Exercise-induced oxidative stress is investigated as a potential performance-limiting factor in human sports medicine. Therefore, the present study aimed to assess whether physiological variables that ... [more ▼]

Exercise-induced oxidative stress is investigated as a potential performance-limiting factor in human sports medicine. Therefore, the present study aimed to assess whether physiological variables that change with exercise intensity were correlated with blood oxidant markers in healthy and heaves-affected horses. Seven healthy horses, 8 heaves-affected in remission and 7 heaves-affected in crisis performed a standardised exercise test (SET) of stepwise increasing intensity. Variables monitored during exercise were heart rate (HR), venous plasma lactate (LA), packed cell volume (PCV) and arterial oxygen tension (PaO2). Oxidant markers (uric acid [UA], 8-iso-PGF2alpha and reduced [GSH] and oxidised glutathione [GSSG]) were analysed in venous peripheral blood sampled at rest (R), at peak-exercise intensity (Emax), 15 (E15) and 60 (E60) min after SET. There was a significant effect of heaves on oxidant markers and, therefore, correlation analyses between physiological variables and oxidant markers were performed separately per horse group. In healthy horses, UA analysed at Emax was positively correlated with LA. Furthermore, GSH analysed at Emax and E15 was positively correlated with PaO2. In healthy and heaves-affected horses in remission, GSH and GSSG determined at Emax were negatively correlated with HR. There was no significant correlation between 8-iso-PGF2alpha and physiological variables. In conclusion, a correlation between the physiological response to exercise and some oxidant markers exists in healthy horses. However, in heaves-affected horses the blood oxidant status is probably more dependant on airway disease than on exercise. Future studies should be undertaken to assess whether antioxidant supplementation might positively influence the oxidant-antiodidant balance in exercising horses. [less ▲]

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See detailCorrelation between exercise parameters and oxidant markers in horses
Kirschvink, Nathalie; Art, Tatiana ULiege; De Moffarts, Brieux et al

in Pflügers Archiv : European Journal of Physiology (2002), 443

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See detailThe Use of Cardboard Bedding Material as Part of an Environmental Control Regime for Heaves-affected Horses: In Vitro Assessment of Airborne Dust and Aeroallergen Concentration and In Vivo Effects on Lung Function
Kirschvink, Nathalie; Di silvestro, F.; Sbai, Ilham ULiege et al

in Veterinary Journal (2002), 163

This study aimed to test whether shredded cardboard is an appropriate minimum-dust bedding material for heaves-affected horses. Results of standardized in vitro measurement of airborne dust and ... [more ▼]

This study aimed to test whether shredded cardboard is an appropriate minimum-dust bedding material for heaves-affected horses. Results of standardized in vitro measurement of airborne dust and aeroallergen concentrations of cardboard bedding were significantly lower than those of common bedding materials. Six heaves-affected horses in clinical remission after pasturing were stabled for two months on cardboard bedding and fed grass silage. Pulmonary function tests (PFT: ventilatory mechanics, arterial blood gases, airway inflammation scoring, bronchoalveolar cytology) were performed before, during and after this period and after stabling the horses in poor hygienic conditions. PFT values measured during and after the stabling period on cardboard bedding were not significantly different from those recorded after the period at pasture or from those of healthy horses, but were significantly different from those recorded in poor hygienic conditions. On basis of the in vitro and in vivo results it can be concluded that cardboard bedding, used in conjunction with low-dust forage, may be appropriate in the provision of minimum-dust management of heaves-affected horses [less ▲]

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See detailEffect of nutritional antioxidant supplementation on systemic and pulmonary antioxidant status, airway inflammation and lung function in heaves-affected horses
Kirschvink, Nathalie; Fievez, Laurence ULiege; Bougnet, V. et al

in Equine Veterinary Journal (2002), 34

An oxidant/antioxidant imbalance in favour of oxidants has been identified as playing a decisive role in the pathogenesis of chronic inflammatory airway diseases. Nutritional antioxidant supplementation ... [more ▼]

An oxidant/antioxidant imbalance in favour of oxidants has been identified as playing a decisive role in the pathogenesis of chronic inflammatory airway diseases. Nutritional antioxidant supplementation might reduce oxidative damage by enhancement of the antioxidant defence, thereby modulating inflammatory processes. In a placebo-controlled, blind study, it was tested whether a dietary antioxidant supplement administered for 4 weeks would improve lung function and reduce airway inflammation in heaves-affected horses. Eight horses in clinical remission of heaves were investigated at rest and after a standardised exercise test before and after treatment with an antioxidant supplement (consisting of a mixture of natural antioxidants including vitamins E and C and selenium from a variety of sources) or placebo (oatfeed pellets without additive). Pulmonary function and exercise tolerance were monitored; systemic and pulmonary lining fluid uric acid, glutathione and 8-epi-PGF(2alpha) were analysed, and bronchoalveolar lavage (BAL) cytology and inflammatory scoring of the airways were performed. The antioxidant treatment significantly improved exercise tolerance and significantly reduced endoscopic inflammatory score. Plasma uric acid concentrations were significantly reduced, suggesting downregulation of the xanthine-dehydrogenase and xanthine-oxydase pathway. Haemolysate glutathione showed a nonsignificant trend to increase, while plasma 8-epi-PGF(2alpha) remained unchanged. Pulmonary markers and BAL cytology were not significantly affected by antioxidant supplementation. The present study suggests that the antioxidant supplement tested modulated oxidant/antioxidant balance and airway inflammation of heaves-affected horses [less ▲]

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See detailEffect of chronic airway inflammation and exercise on pulmonary and systemic antioxidant status of healthy and heaves-affected horses
Kirschvink, Nathalie; Smith, N.; Fievez, Laurence ULiege et al

in Equine Veterinary Journal (2002), 34(6), 563-571

In heaves-affected horses the relation between oxidant status, airway inflammation (AI) and pulmonary function (PF) is unknown. The oxidant status of blood and pulmonary epithelial lining fluid (PELF) of ... [more ▼]

In heaves-affected horses the relation between oxidant status, airway inflammation (AI) and pulmonary function (PF) is unknown. The oxidant status of blood and pulmonary epithelial lining fluid (PELF) of healthy (H, n = 6) and heaves-affected horses in clinical remission (REM, n = 6) and in crisis (CR, n = 7) was assessed at rest, during and after standardised exercise test by measurement of reduced and oxidised glutathione, glutathione redox ratio [GRR%]; uric acid and 8-epi-PGF2alpha. Oxidant status was related to PF parameters (mechanics of breathing and arterial blood gas tension) and Al parameters (bronchoalveolar lavage [BAL] neutrophil % and AI score). Haemolysate glutathione was significantly different between groups and was correlated with PF and AI parameters; GRR in PELF was increased during CR and was correlated with PF and AI parameters. Exercise induced an increase of plasma uric acid that was significantly higher both in REM and CR. PELF 8-epi-PGF2alpha was significantly increased in CR and correlated with PF and AI parameters. These results suggest that oxidative stress occurring in heaves is correlated with PF and AI and may be locally assessed by PELF glutathione status, uric acid and 8-epi-PGF2alpha. Systemic repercussions are reflected by assay of GSH in resting horses and by uric acid in exercising horses. [less ▲]

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See detailEffects of 8-epi-Pgf2alpha on isolated bronchial smooth muscle of healthy and heaves-affected horses
Kirschvink, Nathalie; Art, Tatiana ULiege; Lekeux, Pierre ULiege et al

in Journal of Veterinary Pharmacology & Therapeutics (2001), 24(3), 215-221

8-Epi-PGF2alpha, a prostaglandin-like compound generated by oxidative stress, has been shown to be an in vitro bronchoconstrictor in airways from healthy laboratory animals and healthy humans, but it has ... [more ▼]

8-Epi-PGF2alpha, a prostaglandin-like compound generated by oxidative stress, has been shown to be an in vitro bronchoconstrictor in airways from healthy laboratory animals and healthy humans, but it has never been studied in diseased airways. Here, the bronchoconstrictive capacity of 8-epi-PGF2alpha on isolated bronchial rings (BR) of healthy and heaves-affected horses was evaluated by comparing the maximal effect and the potency of 8-epi-PGF2alpha to those of (1) acetylcholine (ACh), (2) its stereoisomer PGF2alpha and (3) its synthetic receptor agonist, U46619. Furthermore, the potential capacity of 8-epi-PGF2alpha to enhance the cholinergic (ACh) responsiveness of bronchial smooth muscle was investigated. 8-Epi-PGF2alpha contracted BR with a rank order of efficacy of Ach > U44619 > PGF2alpha > 8-epi-PGF2alpha in both healthy and heaves-affected horses. The contractile maximal response elicited by 8-epi-PGF2alpha was significantly smaller than that elicited by the other drugs, but was significantly higher in BR from heaves-affected horses than in those sampled in healthy horses, whilst pD2 values were similar. A subthreshold concentration of 8-epi-PGF2alpha (10-7 M) did not induce in vitro cholinergic hyper-responsiveness in BR of either healthy or heaves-affected horses. In conclusion, it has been demonstrated that 8-epi-PGF2alpha is an in vitro bronchoconstrictor of minor importance in healthy horses, but whose efficacy is significantly increased in heaves-affected horses. [less ▲]

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See detailEffect of isoprostanes on bronchial smooth muscle in healthy and asthma-like horses
Kirschvink, Nathalie; Lekeux, Pierre ULiege; Art, Tatiana ULiege et al

in American Journal of Respiratory & Critical Care Medicine (2000), 161(3), 274

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See detailAssessment of muscle oxygenation in the horse by near infrared spectroscopy
Pringle, John; Roberts, C.; Art, Tatiana ULiege et al

in Equine Veterinary Journal (2000), 32(1), 59-64

This study examined the ability of near infrared spectroscopy (NIRS) to noninvasively determine changes to muscle oxygenation in the resting horse. Five horses had (NIRS) performed over extremity muscle ... [more ▼]

This study examined the ability of near infrared spectroscopy (NIRS) to noninvasively determine changes to muscle oxygenation in the resting horse. Five horses had (NIRS) performed over extremity muscle while under general anaesthesia, first with 8 min limb ischaemia, then systemic hypoxaemia for 5 min. A second group of 6 awake horses had NIRS performed over extremity muscle while being administered hypoxic gas (F(I)O2 0.10) for 5 min, and after return to steady state, limb ischaemia was induced for an additional 5 min. In the anaesthetised horses' ischaemia induced marked and significant muscle deoxygenation of haemoglobin/myoglobin (P<0.01), with corresponding arterial saturation decreasing from 98.9 to 81.9%. Hypoxaemia induced small yet significant muscle deoxygenation (P<0.01) that was 3.2% of the ischaemia deoxygenation signal, with a corresponding decrease in arterial saturation from 98.6 to 90.4%. In the awake horses muscle deoxygenation was not detectable during hypoxia despite reduction of arterial saturation from 97.8 to 86.8%, whereas ischaemia induced rapid and significant deoxygenation of muscle (P<0.05), with corresponding reduction of venous saturation from 78.4 to 75.4%. In neither group of horses was there evidence of cytochrome aa3 reduction, despite complete ischaemia for up to 8 min. NIRS changes in the resting horse muscle clearly differed between ischaemia and hypoxaemia, and can readily show muscle deoxygenation in clinically relevant hypoxaemia in the horse under anaesthesia. Further, as the deoxygenation signal induced by ischaemia was clearly detectable above a background movement artefact, NIRS application to study of muscle oxygenation in the working horse should be explored. [less ▲]

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See detailNear infrared spectroscopy in large animals: optical pathlengh and influence of hair covering and epidemal pigmentation
Pringle, J.; Roberts, C.; Kohl, M. et al

in Veterinary Journal (1999), 158

The effects of epidermal pigmentation and hair covering on the relative transparency of various animal tissues to near infrared (NIR) light were examined, and the pathlengths of NIR light through tissues ... [more ▼]

The effects of epidermal pigmentation and hair covering on the relative transparency of various animal tissues to near infrared (NIR) light were examined, and the pathlengths of NIR light through tissues at four wavelengths in the NIR range were subsequently determined. Black hair covering and black or dark-coloured hooves prevented NIR light from penetration sufficient for conduction of pathlength or NIR spectroscopy measurements. Non-pigmented hair covering of the head did not appear to be a barrier to successful NIR light transmission. Tissues sufficiently transparent to NIR light had the differential pathlength factor (DPF, i.e. the ratio of the observed light pathlength and the geometric light source-detector separation) of NIR light determined by intensity modulated spectroscopy at the wavelengths 744, 806, 834 and 860 nm. Horse gluteal muscles had DPFs of 6.2, 6.2, 6.0, and 5.6, whereas forelimb muscles had DPF of 4.7, 4.4, 4.5 and 3.9 at the respective wavelengths. Sheep heads had DPF of 7.2 +/- 0.3, 5.8 +/- 0.5, 5.5 +/- 0.4 and 4.4 +/- 0.6 (+/- SEM) for the above respective wavelengths, of which the pathlengths all differed significantly from the other, except for between 806 and 834 nm, and 834 and 860 nm. The DPF of horse hooves were 4.8 +/- 0.1, 4.8 +/- 0.1, 4.7 +/- 0.1 and 4.4 +/- 0.1 (SEM) for the above noted wavelengths, of which the pathlength at 744 and 806 nm differed from the pathlength at 860 nm (P>0.05). These results show that NIRS is possible through lighter pigmented hair and epidermal tissues, and provide DPFs of horse feet and muscle and the sheep head that enables quantitative NIRS in these species. [less ▲]

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See detailBronchial hyperresponsiveness to isoprostanes in COPD horses ?
Kirschvink, Nathalie; Bureau, Fabrice ULiege; Art, Tatiana ULiege et al

in Proceedings: Réunion de la Société Belge de Physiologie et de Pharmacologie Fondamentales et Cliniques (1999)

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See detailControl of chorionic obstructive pulmonary disease in the horse
Lekeux, Pierre ULiege; Art, Tatiana ULiege; Roberts, C.

in British Veterinary Journal (The) (1996), 152

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See detailMechanics of breathing during strenuous exercise in Thoroughbred horses
Art, Tatiana ULiege; Anderson, L.; Woakes, A. J. et al

in Respiration Physiology (1990), 82(3), 279-294

The changes induced by exercise on the mechanics of breathing, as well as the simultaneous changes occurring in arterial blood gas tensions and in respiratory gas exchange were investigated in 6 healthy ... [more ▼]

The changes induced by exercise on the mechanics of breathing, as well as the simultaneous changes occurring in arterial blood gas tensions and in respiratory gas exchange were investigated in 6 healthy thoroughbred horses, performing a treadmill exercise of increasing intensity. Respiratory airflow and tidal volume (VT) were measured with ultrasonic flowmeters. Pleural pressure changes were measured by an oesophageal balloon catheter. Gas concentration of the expired air was analysed with a mass spectrometer; the oxygen consumption (VO2) and the carbon dioxide output (VCO2) were computed breath-by-breath. Arterial blood gas values were obtained by sampling from the carotid artery. Between rest and fast gallop VT, respiratory frequency, expired minute ventilation (VE), VO2, VCO2, total pulmonary resistance (RL), mechanical work of breathing (Wrm) and PaCO2 increased significantly while PaO2 decreased significantly. The Wrm.VO2(-1) ratio in galloping horses increased exponentially with VE. This, together with the relationship between the changes in PaO2 and in PaCO2 and the increase in the ventilatory mechanics parameters, suggests that the mechanics of breathing may be one of the factors constraining further increase in ventilation in exercising healthy horses. [less ▲]

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See detailEffect of increasing speed and incline on ventilation in thoroughbred horses exercising on a treadmill
Art, Tatiana ULiege; Anderson, L.; Roberts, c et al

in Archives Internationales de Physiologie et de Biochimie (1989), 97(5), 85

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