Evidence of polystyrene nanoplastic contamination and potential impacts in Mya arenaria clams in the Saint-Lawrence estuary (Canada).

Plastic materials found in the environment are expected to degrade into smaller plastic nanoparticles (NPs) posing a greater toxic risk because they sorb contaminants and pass physiological barriers. Moreover the presence and effects of NPs is difficult to tease out from the contamination background at polluted sites. The purpose of this study was to examine for the presence of polystyrene NPs in feral Mya arenaria clam population near anthropogenic sources of pollution and potential toxic effects. Polystyrene NPs were determined by a newly developed fluorescence-based and size exclusion chromatography methodologies. Clam health status was determined by following changes in air survival time, condition factor, growth, alcohol/aldehyde dehydrogenase (AADH), protein aggregation and lactate dehydrogenase (LDH). In addition, multi-elemental analysis in tissues was also determined. The results revealed that clams collected at 2 polluted sites contained elevated amounts of polystyrene-like NPs between 10 and 110 nm in size based on size exclusion chromatography. Elevated levels of AADH suggest the presence of hydroxylated products and were correlated with plastic NPs in tissues. Moreover, principal component analysis revealed that As, Ca, Cu, Sn and V were closely related to either polystyrene-like NPs in tissues or AADH activity. Although we cannot rule out other pollutants, clams contaminated by polystyrene-like NPs had lower condition, growth rate, air survival time and LDH activity. Increased metal/element contamination reported to sorb onto plastic polymers were also related to NPs in tissues. In conclusion, clams populations close to anthropogenic sources of pollution show evidence of polystyrene-like NPs contamination and could contribute to decreased clam health status.

O 089 - A soft robotic exosuit assisting the paretic ankle in patients post-stroke: Effect on muscle activation during overground walking.

This study compared overground walking with and without exosuit assistance in post-stroke patients. Exosuit-assisted walking was found to improve paretic propulsion and ground clearance during swing, two common gait deviations in stroke patients. No changes in leg muscle activity was found, motivating further study of the exosuit as a tool for gait training during stroke rehabilitation.

A branching process, its application in biology: influence of demographic parameters on the social structure in mammal groups.

Branching processes are widely used in biology. This theoretical tool is used in cell dynamics, epidemics and population dynamics. In population dynamics, branching processes are mainly used to access extinction probabilities of populations, groups or families, with the Galton-Watson branching process. Many mammal species live in socially-structured groups, and the smallest units of these groups are lineages (or families) of kin-related individuals. In many primate species, these lineages are matrilines, as females remain in their natal groups most of the time, whereas males generally disperse. Lineage parameters, such as numbers of matrilines, size of each matriline and average degree of relatedness, could strongly influence the genetic composition of groups. Evidence indicates that division along matrilines could induce substantial differentiation among fission groups. Here, we develop a novel mathematical model based on the branching process theory describing demographic dynamics of groups. The main result of this model is an explicit analytical expression of the joint distribution of numbers of lineages and sizes of socially-structured groups. We investigated the influence of parameters such as natality and mortality on the outcome of the process, including extinction probability. Finally, we discuss this theoretical result with respect to biological significance.

Testing the reliability of noninvasive genetic sampling by comparing analyses of blood and fecal samples in Barbary macaques (Macaca sylvanus).

Genetic studies of wild animal populations are often hindered by difficulties in obtaining blood samples. Recent advances in molecular biology have allowed the use of noninvasive samples as sources of DNA (e.g., hair or feces), but such samples may provide low-quality DNA and prevent the determination of true genotypes in subsequent DNA analysis. We present a preliminary study aimed at assessing the reliability of using fecal samples for genotyping in Barbary macaques (Macaca sylvanus). The test was performed on samples of blood and feces from 11 captive animals, using three dinucleotide microsatellites. The CTAB DNA extraction method was found to be the most relevant for Barbary macaque feces, yielding successful amplification at all loci for 70% of PCRs. All the fecal samples tested gave correct genotypes at least once for each locus when referenced against blood-derived genotypes. An average of 18.3% of PCRs displayed spurious genotypes (false homozygous or false allele). The minimum theoretical probability required to obtain a 100% accurate genotype is 0.74, based on the criterion that a correct genotype is assessed only if it was observed at least twice. The observed probability of obtaining a correct genotype from three PCRs, based on our genotyping results, was greater (0.81 on average) than the minimum threshold. In conclusion, our comparison of blood and fecal samples showed that fecal sampling is a reliable tool for the further study of wild Barbary macaque populations.

Is male-infant caretaking related to paternity and/or mating activities in wild Barbary macaques (Macaca sylvanus)?

In species with a promiscuous mating system, the functions of male-infant caretaking remain unclear in the absence of genetic paternity tests. We tested paternal investment and hypotheses concerning reproductive tactics in wild groups of Barbary macaques, including results of genetic paternity tests. Our study revealed that male-infant caretaking was not related to the probability of paternity. In principle, males could use access to females to estimate paternity. However, we found that mating success was not related to paternity, so males could invest in infants that they had not sired, and caretaking of non-offspring was actually observed. Accordingly, males might be 'deceived' with respect to their paternal investment. In that case, one would expect a positive relation between mating success and the subsequent rate of male caretaking of infants. Such a relation is also lacking, leading to comprehensive rejection of the paternal investment hypothesis in Barbary macaques. By contrast, there was evidence that males showing infant care achieved higher mating frequencies than other males with the mothers of the relevant infants. Thus, male Barbary macaques do not show a 'mate-then-care' pattern, but they do exhibit a 'care-then-mate' pattern.

Genetic differentiation within and between isolated Algerian subpopulations of Barbary macaques (Macaca sylvanus): evidence from microsatellites

This study of wild-living Algerian Barbary macaques (Macaca sylvanus) was designed to examine genetic variability in subpopulations isolated in residual forest patches, in an attempt to obtain data on the effects of habitat fragmentation. The wild population of this species (estimated at a maximum of 15,000) is vulnerable and this study therefore has direct relevance for conservation measures. Data from five microsatellite loci were analysed for 159 individuals from nine different groups living in four isolates in Algeria. Genetic polymorphism was found to be relatively high (4-12 alleles per locus) compared with other genetic markers used in previous studies of this species; mean expected heterozygosity was 65%. The four isolates are all genetically distinct (FST = 0; P < 0.001). Indeed, the results suggest that dispersal is limited even between some social groups within a single isolate. Genetic distances based on models not assuming stepwise mutation (FST and chord distance) gave very similar results and are highly correlated with geographical distances within one isolate but not between isolates. This may indicate that isolation by distance exerts a significant influence within an isolate but that genetic drift prevails between the four isolates. After allowing for variation in sample size, we found no evidence of reduced allelic diversity within small isolates that may have been separated for 250 years or more. The surviving population of Algerian Barbary macaques taken as a whole still shows marked variability in microsatellite alleles, but maintenance of genetic variability over the long term will surely require effective protection of all isolates.

Behavioral responses of Barbary macaques (Macaca sylvanus) to variations in environmental conditions in Algeria.

In this study, the behavioral responses of Barbary macaques to seasonal and interhabitat variations in resource availability were analyzed over an entire annual cycle. Two groups, one in an evergreen cedar-oak forest (Djurdjura) and the other in a deciduous oak forest (Akfadou), were observed. In this paper, references to data on resource availability published elsewhere are made. Time budget has been studied. Variations in foraging and moving time, in day-range lengths, and in time moving in trees have been considered to estimate the variations in foraging effort and thus energy expenditure. Great monthly variations in foraging effort and other activities were observed in both habitats. In early spring, when resource availabilities were maximal, foraging effort was low while monkeys maximized their feeding time (about 5 h/day). In June, during the peak of the birth season and the rearing period, monkeys minimized their feeding time to the benefit of social interactions (to 1.6-2.7 h/day), whatever the food availability, which was low in Akfadou and high in Djurdjura. In addition, foraging effort remained low in Djurdjura, while it increased in Akfadou. Thus, at the beginning of the dry summer period, monkeys in Akfadou were in a less favorable position than those in Djurdjura. At both sites, in periods of food shortage in summer or in winter, monkeys displayed two different strategies. In the former case, their foraging effort increased, while in the second one it remained relatively low. Whatever the foraging effort, monkeys did not reach the same amount of feeding time as in early spring. In the poorest site of Akfadou, foraging effort was globally greater than in the richest site of Djurdjura, especially for adults. At both sites, adult males spent more time feeding than juveniles and less time in social interactions. Results are discussed according to rearing period, temperatures, and day length constraints. The limits of adaptability to different habitats are considered in light of the demographic parameters.

[Inflammatory Gorham disease]. / Une maladie de Gorham inflammatoire.

The case of a 48-year old female with massive osteolysis since the age of 13 years is reported. She had inflammatory flares which resolved spontaneously or after a transient discharge of lymph.

[Progressive and confluent hypomelanosis of the melanodermic metis]. / Hypomélanose maculeuse confluente et progressive du métis mélanoderme.

Melanodermic half-castes may develop a progressive and extensive hypomelanosis presenting as an original skin condition. The course of the disease is characteristic: it occurs mainly in females from 18 to 25 years of age with a progressive development of hypochromic and coalescent macules on the back and abdomen. This disease may regress spontaneously within 5 years and healing seems to be facilitated by UV exposure. Decreased epidermal melanin is the only histological feature. Ultrastructural examination has led to characterize this bizarre disease by a switch from stage IV single melanosomes negroid type to small type I-III aggregated melanosomes (caucasoid phenotype of melanogenesis). Although the pathogenesis of the disorder remains obscure, it may be stated that the variation in skin coloration in these patients is due to a variation in melanosome size and distribution. It is possible that this variation is due to a decrease in production of type IV melanosomes and that this apparent change of ultrastructural phenotype represent the consequence of a simple imbalance in melanosomes production favoring small I to III melanosomes. This disease is not restricted to a limited geographic group: it is present in melanodermic half-castes of different areas and therefore deserves to be known and recognized.

[Demography and reproduction of Macaca sylvanus in different habitats in Algeria]. / Démographie et reproduction de Macaca sylvanus dans différents habitats en Algérie.

Usually described as a cedar forest monkey, the Barbary macaque in effect has colonized a great variety of habitat types. At the moment, it is not known to what extent these different habitats are suitable for the species' survival. We tried to answer this question by comparing the demography of three monkey troops: one lives in a deciduous oak forest; the second lives in an nondeciduous cedar-green oak forest while the third is found on rocky ridges of mountains without any arborescent vegetation. In the three sites, there is a true seasonal breeding season with most births taking place in April to May and most matings occurring in November to December. Details are given on reproduction parameters (sexual activity of females; fertility rates; young survival...). Monkeys densities are higher in cedar forest than in deciduous forest. The smallest density is found on mountain ridges. Forest troops are more numerous, highly stable; their growth rate is better and the population is relatively young. The situation is slightly better still in the cedar forest than in the oak forest with a sex ratio more in favor of females and a better survival of the young. The troop of the mountain ridges is an unstable group ranging from 10 to 25 individuals; the population is aging, with a low birth rate and more male infants surviving compared with females. Demographic differences between sites are discussed according to climate, food availability and human influences (tree-clearing and overgrazing). Conclusions are drawn from this situation, for species conservation.