Predicting range shifts of African apes under global change scenarios

Aim: Modelling African great ape distribution has until now focused on current or past conditions, while future scenarios remain scarcely explored. Using an ensemble forecasting approach, we predicted changes in taxon-specific distribution under future scenarios of climate, land use and human populations for (1) areas outside protected areas (PAs) only (assuming complete management effectiveness of PAs), (2) the entire study region and (3) interspecies range overlap. Location: Tropical Africa. Methods: We compiled occurrence data (n = 5,203) on African apes from the IUCN A.P.E.S. database and extracted relevant climate-, habitat- and human-related predictors representing current and future (2050) conditions to predict taxon-specific range change under a best- and a worst-case scenario, using ensemble forecasting. Results: The predictive performance of the models varied across taxa. Synergistic interactions between predictors are shaping African ape distribution, particularly human-related variables. On average across taxa, a range decline of 50% is expected outside PAs under the best scenario if no dispersal occurs (61% in worst scenario). Otherwise, an 85% range reduction is predicted to occur across study regions (94% worst). However, range gains are predicted outside PAs if dispersal occurs (52% best, 21% worst), with a slight increase in gains expected across study regions (66% best, 24% worst). Moreover, more than half of range losses and gains are predicted to occur outside PAs where interspecific ranges overlap. Main Conclusions: Massive range decline is expected by 2050, but range gain is uncertain as African apes will not be able to occupy these new areas immediately due to their limited dispersal capacity, migration lag and ecological constraints. Given that most future range changes are predicted outside PAs, Africa\u27s current PA network is likely to be insufficient for preserving suitable habitats and maintaining connected ape populations. Thus, conservation planners urgently need to integrate land use planning and climate change mitigation measures at all decision-making levels both in range countries and abroad

Quantitative estimates of glacial refugia for chimpanzees (Pan troglodytes) since the Last Interglacial (120,000 BP).

Paleoclimate reconstructions have enhanced our understanding of how past climates have shaped present-day biodiversity. We hypothesize that the geographic extent of Pleistocene forest refugia and suitable habitat fluctuated significantly in time during the late Quaternary for chimpanzees (Pan troglodytes). Using bioclimatic variables representing monthly temperature and precipitation estimates, past human population density data, and an extensive database of georeferenced presence points, we built a model of changing habitat suitability for chimpanzees at fine spatio-temporal scales dating back to the Last Interglacial (120,000 BP). Our models cover a spatial resolution of 0.0467° (approximately 5.19 km2 grid cells) and a temporal resolution of between 1000 and 4000 years. Using our model, we mapped habitat stability over time using three approaches, comparing our modeled stability estimates to existing knowledge of Afrotropical refugia, as well as contemporary patterns of major keystone tropical food resources used by chimpanzees, figs (Moraceae), and palms (Arecacae). Results show habitat stability congruent with known glacial refugia across Africa, suggesting their extents may have been underestimated for chimpanzees, with potentially up to approximately 60,000 km2 of previously unrecognized glacial refugia. The refugia we highlight coincide with higher species richness for figs and palms. Our results provide spatio-temporally explicit insights into the role of refugia across the chimpanzee range, forming the empirical foundation for developing and testing hypotheses about behavioral, ecological, and genetic diversity with additional data. This methodology can be applied to other species and geographic areas when sufficient data are available

A hybrid reed instrument: an acoustical resonator with a numerically simulated mouthpiece

International audienceA study on the development of a hybrid wind instrument is carried out. An acoustical tube interacts with a numerically simulated mouthpiece in real-time, with the aim to propose in the long term both a tool for objective measurements, and a new musical instrument, easily playable, with unique timbral capacities. This preliminary study focusses on a first prototype, to verify the physical meaningfulness and estimate its potential. A microphone at the tube entrance feeds a numerical model of the reed used to compute the volume flow through the reed channel. This is the output of the numerical part, which is directed to an electrovalve that proportionally modulates the volume flow between the compressed air source and the tube entrance. The hybrid instrument is characterized by studying its parts separately (evaluation of the electrovalve characteristics, impedance measurement of the resonator), but also as a whole by analyzing its behaviour when the parameters of the mouthpiece are varied. Both transients and steady regimes are compared to a fully simulated instrument. We observed a coherent functioning for fundamental frequencies sufficiently below the electrovalves first resonant frequency. The foremost drawbacks are associated to the electrovalves mechanics and to noisy pressure measurements

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MONTPELLIER-BU Pharmacie (341722105) / SudocSudocFranceF

Exercise Capacity, Physical Activity, and Obesity in Adults With Repaired Aortic Coarctation

BACKGROUND: Patients with aortic coarctation (COA) have a reduced exercise capacity and seem to be more prone to adopt a sedentary lifestyle. During clinical practice, we often observe that patients seem to be overweight. However, data on physical activity and weight status in this population are currently not available. OBJECTIVE:: This study aimed to describe weight status, self-reported physical activity levels, and self-perceived health status in adults with repaired COA in comparison with healthy counterparts and to investigate the relationships among exercise capacity, physical activity, weight status, and perceived health status. METHODS: We studied 103 COA patients who underwent cardiopulmonary exercise testing and who completed the Flemish Physical Activity Computerized Questionnaire and the short-form 36 health survey questionnaire. RESULTS: Patients with COA show a significantly lower exercise tolerance than what would be expected in healthy persons (P < .0001). Weight status was similar to the overall Belgian population, but a tendency towards higher body mass index was present. Patients with COA report a lower level of habitual physical activity (P < .05) as well as reductions in perceived vitality, general health, and mental health (P < .05). Parameters of habitual physical activity are related to exercise capacity (total energy expenditure: r = 0.278, P = .0015). The more active COA patients report higher scores of perceived physical functioning, general health, and mental health. Overweight patients did not perform significantly different than patients with a healthy weight did. CONCLUSIONS: Adults with repaired COA have a reduced exercise tolerance, which is related to low physical activity levels. Up to one-third of the COA patients we studied are overweight. As a poor exercise capacity identifies patients at risk for hospitalization and death and obesity might adversely influence the development of cardiovascular disease, it is important to improve the exercise capacity in these patients. Guiding patients toward more physical activity in daily life might therefore be the number 1 preventive measure to be taken in this patient group.status: publishe

Determinants of physical activity in young adults with tetralogy of Fallot

BACKGROUND: Although sports participation is allowed to most adult patients with corrected tetralogy of Fallot, a reduced exercise tolerance and reduced perceived physical functioning is often present in these patients. We aimed to investigate daily physical activity in adults with tetralogy of Fallot and to investigate the underlying determinants of physical activity in daily life. METHODS: We studied 73 patients with tetralogy of Fallot (53 male; mean age 27.3 ± 7.9 years) who underwent echocardiography and cardiopulmonary exercise testing, and who completed questionnaires about physical activity and perceived health status. All variables were compared with data from a general population. Relationships were studied by Pearson or Spearman correlation coefficients with correction for multiple testing. RESULTS: Patients were significantly less active compared with the general population (p > 0.05), 55% of all patients were sedentary, 27% had an active or moderately active lifestyle, and 18% of the group had a vigorously active lifestyle. Peak oxygen uptake (71 ± 16%; p < 0.0001) was significantly reduced and related to reduced physical activity levels (r = 0.229; p = 0.017) and perceived physical functioning (r = 0.361; p = 0.002). CONCLUSIONS: Adult patients with tetralogy of Fallot have a sedentary lifestyle and are less active than the general population. Inactivity significantly contributes to reduced exercise capacity, in addition to the impairment based on the cardiac condition. Moreover, reduced exercise capacity and the intensity of sports performed in daily life are related to perceived physical functioning. Individual patient counselling on physical activity might be a low-cost, high-benefit measure to be taken in this patient population.status: publishe

Predictors of mid-term event-free survival in adults with corrected Tetralogy of Fallot

Background Patients who underwent corrective surgery for Tetralogy of Fallot (TOF) have increased long-term risk of cardiovascular morbidity and mortality. Yet limited information is available on how to evaluate risk in this population. Therefore the aim of this study was to assess the prognostic value of several demographic, clinical and exercise variables in these patients. Methods Between 2000 and 2003, 91 adults (age 26.2 ±7.8 years; 63 male, 28 female) who had corrective surgery for TOF during childhood, underwent a cardiopulmonary exercise test until exhaustion and echocardiography. During a follow-up of 7.3 ± 1.2 years (range 0.9 to 9.3 years), 2 patients died at an age of 17 and 41 years old, and 26 patients required at least 1 cardiac-related intervention (6 balloon dilatation, 7 EPU with ablation, 10 pulmonary valve replacement, 4 ICD-implantation, 1 pacemaker implantation) at a mean age of 28.9 ± 7.9 years. Cox proportional-hazards multiple regression analysis was used to assess the relation between baseline variables and event-free survival. Results At multivariate Cox analysis, NYHA-class (hazard ratio: 24.069, p=0.0006), right ventricular function (hazard ratio: 5.382, p=0.0019), age (hazard ratio: 1.168, p=0.0087), age at correction (hazard ratio: 0.761, p=0.0317), percentage of predicted peak oxygen uptake (peak VO2%) (hazard ratio: 0.945, p=0.0062), oxygen uptake efficiency slope (OUES) (hazard ratio: 1.002, p=0.0010), and ventilatory efficiency-slope (VE/VCO2-slope) (hazard ratio: 1.136, p=0.0476) were significantly related to the incidence of death/cardiac-related intervention during medium follow-up among demographic, clinical, echocardiographic and exercise variables. Conclusions Early corrective surgery and a well preserved right ventricular function as assessed by echocardiography are associated with a better outcome in adults with corrected TOF. Furthermore, cardiopulmonary exercise testing provides important prognostic information; peak VO2%, OUES and VE/VCO2-slope are independent predictors for mortality/need for cardiac-related intervention in patients with corrected Tetralogy of Fallot.status: publishe

Evolution of exercise capacity with age in patients with atrial switch repair for transposition of the great arteries

Purpose Results of cardiopulmonary exercise testing in patients with atrial switch repair for transposition of the great arteries show a significantly reduced exercise capacity. Our aim is to investigate the evolution of this reduced exercise capacity. Methods 45 patients (30 male, 15 female) with atrial switch repair for transposition of the great arteries performed 159 cardiopulmonary exercise tests until exhaustion (3.,53±0.66 tests per patient) with an interval of at least 1 year. Mean age at first test was 19.6±7.34 years old. Time between the first and the last exercise test was 6.37 ± 1.44 years (range 3 to 9 years). Peak VO2 and VO2 at anaerobic threshold were measured and expressed as a percentage of normal values according to age and gender. Mean rate of change was calculated for each patient by linear regression analysis. Results Mean percentages of peak VO2 and anaerobic threshold were significantly lower than a healthy population (p<0.0001). Mean peak VO2 at the first exercise test was 68.4±14.1% and averaged 62.1±13.5% at the last test. Mean anaerobic threshold at the first exercise test was 72.7±17.2%, and 62.3±16.9% at the last test. Differences between first and last exercise tests were not significant by paired t-test. Mean rate of change was -1.34±3.22% per year for peak VO2 and -1.51±3.62% per year for anaerobic threshold, which is significantly different from the healthy reference population (p=0.008 and p=0.015 respectively). Conclusions Patients who underwent atrial switch repair for transposition of the great arteries have a reduced exercise capacity, as expressed by peak VO2 and anaerobic threshold, and this exercise capacity declines faster with age compared to a healthy population.status: publishe