Search

The aim of this study is to evaluate if the sweat produced by COVID-19 persons (SARS-CoV-2 PCR positive) has a different odour for trained detection dogs than the sweat produced by non COVID-19 persons. The study was conducted on 3 sites, following the same protocol procedures, and involved a total of 18 dogs. A total of 198 armpits sweat samples were obtained from different hospitals. For each involved dog, the acquisition of the specific odour of COVID-19 sweat samples required from one to four hours, with an amount of positive samples sniffing ranging from four to ten. For this proof of concept, we kept 8 dogs of the initial group (explosive detection dogs and colon cancer detection dogs), who performed a total of 368 trials, and will include the other dogs in our future studies as their adaptation to samples scenting takes more time.The percentages of success of the dogs to find the positive sample in a line containing several other negative samples or mocks (2 to 6) were 100p100 for 4 dogs, and respectively 83p100, 84p100, 90p100 and 94p100 for the others, all significantly different from the percentage of success that would be obtained by chance alone.We conclude that there is a very high evidence that the armpits sweat odour of COVID-19+ persons is different, and that dogs can detect a person infected by the SARS-CoV-2 virus.

Background Despite the context of several national warnings, antipsychotics drugs are commonly used to treat behavioural and psychological symptoms in dementia (BPSD). Aim To observe a decrease of antipsychotic drug prescription, in old NH (nursing homes) residents with dementia, after an awareness of their general practitioner. Methods Observational, prospective, multicenter study. The study population corresponds to NH residents with dementia, and antipsychotic drug consumption, in nursing homes volunteered to participate. Awareness-raising is carried out through information documents. The evaluation criteria is the proportion of residents under antipsychotics after sensitization. Results out of the 30 nursing homes included, 26.7% of the patients were prescribed at least one antipsychotic and 15% were both demented and under antipsychotics. A total of 317 residents with dementia and antipsychotics were included 15% of the total NH population. Psychotropic drug co-prescriptions was very frequent 43.2% also used benzodiazepines, 37.2% anxiolytics and 33.1% antidepressants. Agitation, aggressiveness, opposition to care and wandering were the most commonly BPSD encountered. After a first sensitization, we obtained a 15.5% decrease of antipsychotic prescriptions. Conclusion A personalized sensitization towards GP allowed a reduction of antipsychotic drugs prescription in NH residents with dementia and BPSD.

Aggregation behaviour is the tendency for animals to group together, which may have important consequences on individual fitness. We used a combination of experimental and simulation approaches to study how genetic variation and social environment interact to influence aggregation dynamics in Drosophila . To do this, we used two different natural lines of Drosophila that arise from a polymorphism in the foraging gene (rovers and sitters). We placed groups of flies in a heated arena. Flies could freely move towards one of two small, cooler refuge areas. In groups of the same strain, sitters had a greater tendency to aggregate. The observed behavioural variation was based on only two parameters: the probability of entering a refuge and the likelihood of choosing a refuge based on the number of individuals present. We then directly addressed how different strains interact by mixing rovers and sitters within a group. Aggregation behaviour of each line was strongly affected by the presence of the other strain, without changing the decision rules used by each. Individuals obeying local rules shaped complex group dynamics via a constant feedback loop between the individual and the group. This study could help to identify the circumstances under which particular group compositions may improve individual fitness through underlying aggregation mechanisms under specific environmental conditions.

Organisms that face behavioural challenges can use different types of information to guide their decisions. First, they can use the personal information they sample in their environment. Second, they can use the inadvertent social information provided by the behaviour of conspecifics or heterospecifics (i.e. public information). Currently, little is known about the interaction between genetic variation and the use of personal versus public information in natural populations. Here, we investigated whether a natural genetic polymorphism affects the use of personal versus public information in a spatial learning task in Drosophila melanogaster . We found that genetic variation at the foraging locus interacts with social context during spatial learning. While both allelic variants are able to use personal and public information to improve their navigation during 10 training trials, a probe trial revealed that individuals carrying the for R (rover) allele rely mainly on personal information, whereas individuals carrying the for s (sitter) allele either use or display more public information than rovers. Accordingly, transfer of social information is more important in groups of sitters than in groups of rovers. These results suggest that a positive feedback loop can occur between alleles promoting group living, such as for s , and the use and/or display of public information, ultimately providing the opportunity for the joint evolution of sociality and cultural traits.