[Invited] Ultra low power Cochlea for biodiversity monitoring

National audienceThis talk relates the architecture, design, and experimental characterization of an ultra low power consumption bioinspired artificial Cochlea, intended to biodiversity monitoring. So far, it has been been calibrated to extract Cetacean acoustic features (sperm whales). The output are spikes (electrical pulses) available through a number of frequency channels (defining the cochlea parallel outputs), generated whenever some energy of the acoustic signal is sensed on a channel. The main application is classification through spiking neural networks, while some other potential applications are possibl

3D diarization of a sperm whale click cocktail party by an ultra high sampling rate portable hydrophone array for assessing individual cetacean growth curves

International audiencePassive acoustics allow us to study group of animals and obtain information that could not be gathered through other methods. In this paper we study a set of near-field audiovisual recordings of a sperm whale pod, acquired with a specific ultra high-frequency and small aperture antenna. This antenna is equiped of the JASON DAC, allowing up to 5 channels recordings at 2 MHz sampling rate. This high velocity recording allows to reduce the size of the array, while keeping good angle of arrival resolution. We then demonstrate how TDoA and non linear solver yield to the localisation of nearly all the clicks emitted by the animal that are filmed. Such characterization of their vocalizations, correlated to individual identifications from visual identification opens avenue to possible acoustic individual signature

Study of Short Bunches at the Free Electron Laser CLIO

International audienceCLIO is a Free Electron Laser based on a thermionic electron gun. In its normal operating mode it delivers electron 8 pulses but studies are ongoing to shorten the pulses to about 1 ps. We report on simulations showing how the pulse can be shortened and the expected signal yield from several bunch length diagnostics (Coherent Transition Radiation, Coherent Smith Purcell Radiation)

Infrared spectroscopy of mass-selected ions in FTICR and QIT mass spectrometers

CLIO Laser power (3-90 um) + OPOs CLIO Laser power for various electron energies CLIO characteristics : • infrared domain from 100 to 3000 cm-1 overview of the « infrared fingerprint » region • continuous & rapid tuneability full spectrum (800-1600cm-1) in typically 1 hour • spectral width around 0.2-0.5 % of central wavenumber (i.e. from from 8 to 4 cm-1) • continuous high power over all range (~800mW) time time 40 msec 8 sec 1 psec 16 nsec =60-70 J CLIO : a pulsed laser with a particular time structur

Study of a Smith-Purcell Radiation-Based Longitudinal Profile Monitor at the CLIO Free Electron Laser

International audienceWe report on measurements of Coherent Smith-Purcell radiation at the CLIO Free Electron Laser. Smith-Purcell radiation is emitted when a grating is brought close from a bunch of relativistic particles. When the bunch is sufficiently short coherent radiation is emitted. This coherent radiation encodes the longitudinal form factor of the bunch and can therefore be used as a longitudinal profile monitor. With its short pulses and high charge the 45 MeV Linac of CLIO is a good location to test advanced longitudinal profile diag- nostics. The results will be compared with measurements using the RF dephasing. induced energy dispersion

Underwater photo-identification of marine megafauna: an identity card catalogue of sperm whales (Physeter macrocephalus) off Mauritius Island

The long-term monitoring of long-lived animal populations often requires individual identification. For cetacean populations, this identification is mostly based on morphological characters observable from a boat such as shape, spots and cuts of the back, caudal and dorsal fins. This is well suited for species easily displaying their caudal fins, such as the humpback whales Megaptera novaeangliae, or those whose skin pigmentation patterns enable individual identification. However, for elusive or shier species such as the sperm whales Physeter macrocephalus, this approach may be more challenging as individuals display a rather uniform skin pigmentation. They also do not show very often their caudal fin that must be photographed perpendicularly to the water surface, vertically and fully emerged, uneasing the individual identification from a boat. Immature sperm whales that usually have a caudal fin without any distinctive marks may sometimes be excluded from photo-identification catalogues. Within the framework of the Maubydick project, focusing on the long-term monitoring of sperm whales in Mauritius, passive underwater observation and video recording were used to identify long-lasting body markers (e.g., sex, ventral white markings, cut outs of fins) to improve individual identification. A catalogue of individual identity cards was developed and 38 individuals were recorded (six adult males, 18 adult females and 14 immatures). This catalogue was used in the field and enabled observers to record some nearly-daily and yearly recaptures. Advantages and disadvantages of this method are presented here. Such catalogues represent a robust baseline for conducting behavioural, genetic and acoustic studies in marine megafauna social species. Benefits of such newly acquired knowledge are of first importance to implement relevant conservation plans in the marine realm

Kin relationships in cultural species of the marine realm: case study of a matrilineal social group of sperm whales off Mauritius island, Indian Ocean

International audienceUnderstanding the organization and dynamics of social groups of marine mammals through the study of kin relationships is particularly challenging. Here, we studied a stable social group of sperm whales off Mauritius, using underwater observations, individual-specific identification, non-invasive sampling and genetic analyses based on mitochondrial sequencing and microsatellite profiling. Twenty-four sperm whales were sampled between 2017 and 2019. All individuals except one adult female shared the same mitochondrial DNA (mtDNA) haplotype—one that is rare in the western Indian Ocean—thus confirming with near certainty the matrilineality of the group. All probable first- and second-degree kin relationships were depicted in the sperm whale social group: 13 first-degree and 27 second-degree relationships were identified. Notably, we highlight the likely case of an unrelated female having been integrated into a social unit, in that she presented a distinct mtDNA haplotype and no close relationships with any members of the group. Investigating the possible matrilineality of sperm whale cultural units (i.e. vocal clans) is the next step in our research programme to elucidate and better apprehend the complex organization of sperm whale social groups

Study of behaviours and emitted codas during sperm whales social interactions

International audienceSperm whales live in the matrilineal population structure based on complex social interactions. Groups of 10-20 adult females stay together and raise their offspring. During social activities, they emit specific patterned time sequences of clicks, called codas. These codas are also the social unit acoustic signature. However, no associations were already done between these emitted sounds and behaviours. To answer this question, we used a dataset including simultaneous video and acoustic recordings during sperm whale activities close to the sea surface. In 2017 and 2018, 114 days of observations for 25h33min was done. A total of 1,810 behaviours and of 1,324 codas were extracted. We analyzed their internal structures, based of number of clicks and also the variation of inter-click intervals. Results showed firstly that the 8-clicks codas were the most frequent sequences for this social unit, and secondly that codas seems to be call and contact signals for this haptic species