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Abidjan, Ivory Coast

Lemoine M.,Imperial College London | Eholie S.,Felix Houphouet-Boigny University | Lacombe K.,Saint Antoine Hospital | Lacombe K.,Paris-Sorbonne University
Journal of Hepatology | Year: 2015

The burden of liver disease may dramatically increase in the near future in Africa, where screening and access to care and treatment are hampered by inadequate disease surveillance, lack of high-quality tools to assess chronic liver disease, and underestimated needs for human and financial resources. Chronic hepatitis may be considered as silent and neglected killer, fuelled by many years of global inertia from stakeholders and policy makers alike. However, the global battle against viral hepatitis is facing a new era owing to the advent of highly effective drugs, innovative tools for screening and clinical follow-up, and recent signs that governments, advocacy groups and global health organizations are mobilizing to advocate universal accessto- treatment. This review details the barriers to prevention, screening and treatment of viral hepatitis on the African continent, focuses on the urgent need for operational and research programmes, and suggests integrated ways to tackle the global epidemic. © 2014 European Association for the Study of the Liver.

Janmaat K.R.L.,Max Planck Institute for Evolutionary Anthropology | Polansky L.,Max Planck Institute for Evolutionary Anthropology | Polansky L.,University of California at Davis | Ban S.D.,Max Planck Institute for Evolutionary Anthropology | And 2 more authors.
Proceedings of the National Academy of Sciences of the United States of America | Year: 2014

Not all tropical fruits are equally desired by rainforest foragers and some fruit trees get depleted more quickly and carry fruit for shorter periods than others. We investigated whether a ripe-fruit specialist, the chimpanzee (Pan troglodytes verus), arrived earlier at breakfast sites with very ephemeral and highly sought-after fruit, like figs, than sites with less ephemeral fruit that can be more predictably obtained throughout the entire day. We recorded when and where five adult female chimpanzees spent the night and acquired food for a total of 275 full days during three fruit-scarce periods in a West African tropical rainforest. We found that chimpanzees left their sleeping nests earlier (often before sunrise when the forest is still dark) when breakfasting on very ephemeral fruits, especially when they were farther away. Moreover, the females positioned their sleeping nests more in the direction of the next day's breakfast sites with ephemeral fruit compared with breakfast sites with other fruit. By analyzing departure times and nest positioning as a function of fruit type and location, while controlling for more parsimonious explanations, such as temperature, we found evidence that wild chimpanzees flexibly plan their breakfast time, type, and location after weighing multiple disparate pieces of information. Our study reveals a cognitive mechanism by which largebrained primates can buffer the effects of seasonal declines in food availability and increased interspecific competition to facilitate first access to nutritious food.We discuss the implications for theories on hominoid brain-size evolution.

Ban S.D.,Max Planck Institute for Evolutionary Anthropology | Ban S.D.,Felix Houphouet-Boigny University | Boesch C.,Max Planck Institute for Evolutionary Anthropology | Janmaat K.R.L.,Max Planck Institute for Evolutionary Anthropology
Animal Cognition | Year: 2014

The use of spatio-temporal memory has been argued to increase food-finding efficiency in rainforest primates. However, the exact content of this memory is poorly known to date. This study investigated what specific information from previous feeding visits chimpanzees (Pan troglodytes verus), in Taï National Park, Côte d’Ivoire, take into account when they revisit the same feeding trees. By following five adult females for many consecutive days, we tested from what distance the females directed their travels towards previously visited feeding trees and how previous feeding experiences and fruit tree properties influenced this distance. To exclude the influence of sensory cues, the females’ approach distance was measured from their last significant change in travel direction until the moment they entered the tree’s maximum detection field. We found that chimpanzees travelled longer distances to trees at which they had previously made food grunts and had rejected fewer fruits compared to other trees. In addition, the results suggest that the chimpanzees were able to anticipate the amount of fruit that they would find in the trees. Overall, our findings are consistent with the hypothesis that chimpanzees act upon a retrieved memory of their last feeding experiences long before they revisit feeding trees, which would indicate a daily use of long-term prospective memory. Further, the results are consistent with the possibility that positive emotional experiences help to trigger prospective memory retrieval in forest areas that are further away and have fewer cues associated with revisited feeding trees. © 2014, Springer-Verlag Berlin Heidelberg.

Janmaat K.R.L.,Max Planck Institute for Evolutionary Anthropology | Ban S.D.,Max Planck Institute for Evolutionary Anthropology | Ban S.D.,Felix Houphouet-Boigny University | Boesch C.,Max Planck Institute for Evolutionary Anthropology
Animal Behaviour | Year: 2013

We studied the nature of information that frugivorous foragers take into account to increase their chances of discovering bountiful fruit crops. We recorded the foraging behaviour of five adult female chimpanzees, Pan troglodytes verus, for continuous periods of 4-8 weeks, totalling 275 full days, throughout multiple fruiting seasons in the Taï National Park, CÔte d'Ivoire. We found that chimpanzees fed on individual trees that were significantly larger than other available and reproductively mature trees of the same species, especially if their fruit emitted an obvious smell. Trees that were merely checked for edible fruit, but where monitoring could not have been triggered by olfactory or auditory cues because the tree did not carry fruit, were also significantly larger. Most trees were monitored along the way during travel, but 13% were approached in a goal-directed manner (assessed using a 'change point test'). These approaches were unlikely to have been initiated by visual cues and occurred more often when females foraged solitarily and when trees were large as opposed to small. Our results suggest that goal-directed monitoring is guided by a long-term 'what-where' memory of the location of large potential food sources. These findings were confirmed in a quasiexperiment that tested which of 15 876 potential food trees with different crown sizes were approached in a goal-directed manner. Observations on one female who was followed intensively over 3 consecutive years indicated that monitoring probability was highest for trees with which she had become more familiar through frequent previous visits and that had carried more fruit, suggesting that she was able to remember this information across fruiting seasons. Long-term phenological data on individual trees indicated that the interval between successive fruiting seasons, and hence the 'memory window' of chimpanzees required for effective monitoring activities, could be up to 3 years. © 2013 The Association for the Study of Animal Behaviour.

Janmaat K.R.L.,Max Planck Institute for Evolutionary Anthropology | Ban S.D.,Max Planck Institute for Evolutionary Anthropology | Ban S.D.,Felix Houphouet-Boigny University | Boesch C.,Max Planck Institute for Evolutionary Anthropology
Animal Cognition | Year: 2013

Fruit foragers are known to use spatial memory to relocate fruit, yet it is unclear how they manage to find fruit in the first place. In this study, we investigated whether chimpanzees (Pan troglodytes verus) in the Taï National Park make use of fruiting synchrony, the simultaneous emergence of fruit in trees of the same species, which can be used together with sensory cues, such as sight and smell, to discover fruit. We conducted observations of inspections, the visual checking of fruit availability in trees, and focused our analyses on inspections of empty trees, so to say "mistakes". Learning from their "mistakes", we found that chimpanzees had expectations of finding fruit days before feeding on it and significantly increased inspection activity after tasting the first fruit. Neither the duration of feeding nor density of fruit-bearing trees in the territory could account for the variation in inspection activity, which suggests chimpanzees did not simply develop a taste for specific fruit on which they had fed frequently. Instead, inspection activity was predicted by a botanical feature-the level of synchrony in fruit production of encountered trees. We conclude that chimpanzees make use of the synchronous emergence of rainforest fruits during daily foraging and base their expectations of finding fruit on a combination of botanical knowledge founded on the success rates of fruit discovery, and a categorization of fruit species. Our results provide new insights into the variety of food-finding strategies employed by primates and the adaptive value of categorization capacities. © 2013 Springer-Verlag Berlin Heidelberg.

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