10 research outputs found
Chimpanzee accumulative stone throwing
Get PDFThe study of the archaeological remains of fossil hominins must rely on reconstructions to elucidate the behaviour that may have resulted in particular stone tools and their accumulation. Comparatively, stone tool use among living primates has illuminated behaviours that are also amenable to archaeological examination, permitting direct observations of the behaviour leading to artefacts and their assemblages to be incorporated. Here, we describe newly discovered stone tool-use behaviour and stone accumulation sites in wild chimpanzees reminiscent of human cairns. In addition to data from 17 mid- to long-term chimpanzee research sites, we sampled a further 34 Pan troglodytes communities. We found four populations in West Africa where chimpanzees habitually bang and throw rocks against trees, or toss them into tree cavities, resulting in conspicuous stone accumulations at these sites. This represents the first record of repeated observations of individual chimpanzees exhibiting stone tool use for a purpose other than extractive foraging at what appear to be targeted trees. The ritualized behavioural display and collection of artefacts at particular locations observed in chimpanzee accumulative stone throwing may have implications for the inferences that can be drawn from archaeological stone assemblages and the origins of ritual sites
Human impact erodes chimpanzee behavioral diversity
Get PDFChimpanzees possess a large number of behavioral and cultural traits among nonhuman species. The “disturbance hypothesis” predicts that human impact depletes resources and disrupts social learning processes necessary for behavioral and cultural transmission. We used a dataset of 144 chimpanzee communities, with information on 31 behaviors, to show that chimpanzees inhabiting areas with high human impact have a mean probability of occurrence reduced by 88%, across all behaviors, compared to low-impact areas. This behavioral diversity loss was evident irrespective of the grouping or categorization of behaviors. Therefore, human impact may not only be associated with the loss of populations and genetic diversity, but also affects how animals behave. Our results support the view that “culturally significant units” should be integrated into wildlife conservation
Chimpanzee accumulative stone throwing
Get PDFThe study of the archaeological remains of fossil hominins must rely on reconstructions to elucidate the behaviour that may have resulted in particular stone tools and their accumulation. Comparatively, stone tool use among living primates has illuminated behaviours that are also amenable to archaeological examination, permitting direct observations of the behaviour leading to artefacts and their assemblages to be incorporated. Here, we describe newly discovered stone tool-use behaviour and stone accumulation sites in wild chimpanzees reminiscent of human cairns. In addition to data from 17 mid- to long-term chimpanzee research sites, we sampled a further 34 Pan troglodytes communities. We found four populations in West Africa where chimpanzees habitually bang and throw rocks against trees, or toss them into tree cavities, resulting in conspicuous stone accumulations at these sites. This represents the first record of repeated observations of individual chimpanzees exhibiting stone tool use for a purpose other than extractive foraging at what appear to be targeted trees. The ritualized behavioural display and collection of artefacts at particular locations observed in chimpanzee accumulative stone throwing may have implications for the inferences that can be drawn from archaeological stone assemblages and the origins of ritual sites.This is an article from Scientific Reports 6 (2016): 22219, doi:10.1038/srep22219. Posted with permission.</p
Chimpanzee accumulative stone throwing
No full textThe study of the archaeological remains of fossil hominins must rely on reconstructions to elucidate the behaviour that may have resulted in particular stone tools and their accumulation. Comparatively, stone tool use among living primates has illuminated behaviours that are also amenable to archaeological examination, permitting direct observations of the behaviour leading to artefacts and their assemblages to be incorporated. Here, we describe newly discovered stone tool-use behaviour and stone accumulation sites in wild chimpanzees reminiscent of human cairns. In addition to data from 17 mid- to long-term chimpanzee research sites, we sampled a further 34 Pan troglodytes communities. We found four populations in West Africa where chimpanzees habitually bang and throw rocks against trees, or toss them into tree cavities, resulting in conspicuous stone accumulations at these sites. This represents the first record of repeated observations of individual chimpanzees exhibiting stone tool use for a purpose other than extractive foraging at what appear to be targeted trees. The ritualized behavioural display and collection of artefacts at particular locations observed in chimpanzee accumulative stone throwing may have implications for the inferences that can be drawn from archaeological stone assemblages and the origins of ritual sites
Outcomes of patients with systemic sclerosis treated with rituximab in contemporary practice: a prospective cohort study.
No full textObjective To assess the safety and efficacy of rituximab in systemic sclerosis (SSc) in clinical practice. Methods We performed a prospective study including patients with SSc from the European Scleroderma Trials and Research (EUSTAR) network treated with rituximab and matched with untreated patients with SSc. The main outcomes measures were adverse events, skin fibrosis improvement, lung fibrosis worsening and steroids use among propensity score-matched patients treated or not with rituximab. Results 254 patients were treated with rituximab, in 58% for lung and in 32% for skin involvement. After a median follow-up of 2 years, about 70% of the patients had no side effect. Comparison of treated patients with 9575 propensity-score matched patients showed that patients treated with rituximab were more likely to have skin fibrosis improvement (22.7 vs 14.03 events per 100 person-years; OR: 2.79 [1.47-5.32]; p=0.002). Treated patients did not have significantly different rates of decrease in forced vital capacity (FVC)>10% (OR: 1.03 [0.55-1.94]; p=0.93) nor in carbon monoxide diffusing capacity (DLCO) decrease. Patients having received rituximab were more prone to stop or decrease steroids (OR: 2.34 [1.56-3.53], p<0.0001). Patients treated concomitantly with mycophenolate mofetil had a trend for better outcomes as compared with patients receiving rituximab alone (delta FVC: 5.22 [0.83-9.62]; p=0.019 as compared with controls vs 3 [0.66-5.35]; p=0.012). Conclusion Rituximab use was associated with a good safety profile in this large SSc-cohort. Significant change was observed on skin fibrosis, but not on lung. However, the limitation is the observational design. The potential stabilisation of lung fibrosis by rituximab has to be addressed by a randomised trial
Update on the profile of the EUSTAR cohort: an analysis of the EULAR Scleroderma Trials and Research group database
No full textObjectives Systemic sclerosis (SSc) is a rare disease requiring multicentre collaboration to reveal comprehensive details of disease-related causes for morbidity and mortality.Methods The European League Against Rheumatism (EULAR) Scleroderma Trials and Research (EUSTAR) group initiated a database to prospectively gather key data of patients with SSc using a minimal essential dataset that was reorganised in 2008 introducing new items. Baseline visit data of patients who were registered between 2004 and 2011 were analysed using descriptive statistics.Results In June 2011, 7655 patients (2838 with diffuse cutaneous (dc) and 4481 with limited cutaneous (lc) SSc who fulfilled the American College of Rheumatology diagnostic criteria had been registered in 174 centres, mainly European. The most prominent hallmarks of disease were Raynaud's phenomenon (96.3%), antinuclear antibodies (93.4%) and a typical capillaroscopic pattern (90.9%). Scleroderma was more common on fingers and hands than on any other part of the skin. Proton pump inhibitors (65.2%), calcium channel blockers (52.7%), and corticosteroids (45.3%) were most often prescribed. Among the immunosuppressant agents, cyclophosphamide was used more often in dcSSc than in lcSSc.Conclusions The EUSTAR database provides an abundance of information on the true clinical face of SSc that will be helpful in improving the classification of SSc and its subsets and for developing more specific therapeutic recommendations
Outcomes of patients with systemic sclerosis treated with rituximab in contemporary practice: a prospective cohort study
No full textTo assess the safety and efficacy of rituximab in systemic sclerosis (SSc) in clinical practice
