Using two drones to simultaneously monitor visual and acoustic behaviour of gray whales (Eschrichtius robustus) in Baja California, Mexico

This study provides an initial demonstration of a combined two-UAV (Unmanned Aerial Vehicle) system for measuring the underwater source levels and behavioural context of vocal and non-vocal marine mammal signals, information that is highly ecologically-relevant in terms of understanding how a species interacts and copes with conspecifics and its acoustic environment. Although the calls of a few species are well known, major gaps exist in our knowledge about the relationship between vocal output and behavioural context, gender and age for most species. Accurate parameter estimates (e.g., typical source levels, frequency ranges, and temporal characteristics of animal sounds) relevant to their behaviour (activities such as foraging, migrating, mating, or parental care) are needed to establish use of critical habitats (when monitored by acoustics) or to assess potential effects of anthropogenic sound exposure (including reduction of the detection space of sounds used for communication). The emergence of UAVs provides new perspectives and data collection capabilities for marine mammal research.  Although UAVs have been frequently exploited for visual observations of whales, most approaches for monitoring and recording sounds from individual whales are still performed using overside hydrophones from a boat or using acoustic tags attached to the animals. Laguna San Ignacio (LSI), Mexico, is one of the breeding and calving grounds of the Eastern North Pacific gray whale (Eschrichtius robustus) population. LSI area's restricted geography, combined with the short dive times of the whales, provided an excellent field laboratory to test a dual drone approach. We used two UAVs: one to obtain acoustic measurements close to the whales and another one to obtain overhead visual observations. For the acoustic drone, a hydrophone (SoundTrap) was suspended via a 2-m line to a waterproof UAV quadcopter (Swellpro), which has the ability to take off and land from the surface of water. Simultaneously, the visual drone (DJI) monitored the whales in the area. Between 27 February and 17 March 2019, we simultaneously recorded underwater gray whale sounds and visual behavioural observations.  During 92 min of underwater acoustic recordings, the acoustic drone recorded 11 call types. By timesynching underwater audio with the behavioural video, we obtained new insights into the source levels and functions of various quiet underwater sound that are difficult to impossible to obtain with standard methods. To our knowledge, no studies combining overhead visual observations and underwater acoustic recordings to describe acoustic behaviour and sound parameters of calls have been previously published

Regulation of fc receptor endocytic trafficking by ubiquitination.

Most immune cells, particularly phagocytes, express various receptors for the Fc portion of the different immunoglobulin isotypes (Fc receptors, FcRs). By binding to the antibody, they provide a link between the adaptive immune system and the powerful effector functions triggered by innate immune cells such as mast cells, neutrophils, macrophages, and NK cells. Upon ligation of the immune complexes, the downstream signaling pathways initiated by the different receptors are quite similar for different FcR classes leading to the secretion of preformed and de novo synthesized pro-inflammatory mediators. FcR engagement also promotes negative signals through the combined action of several molecules that limit the extent and duration of positive signaling. To this regard, ligand-induced ubiquitination of FcRs for IgE (FcepsilonR) and IgG (FcgammaR) has become recognized as a key modification that generates signals for the internalization and/or delivery of engaged receptor complexes to lysosomes or cytoplasmic proteasomes for degradation, providing negative-feedback regulation of Fc receptor activity. In this review, we discuss recent advances in our understanding of the molecular mechanisms that ensure the clearance of engaged Fcepsilon and Fcgamma receptor complexes from the cell surface with an emphasis given to the cooperation between the ubiquitin pathway and endosomal adaptors including the endosomal sorting complex required for transport (ESCRT) in controlling receptor internalization and sorting along the endocytic compartments

Energy dependence of hyperon production in nucleus-nucleus collisions at SPS

A measurement of strange baryon and antibaryon production in Pb–Pb collisions has been carried out by the NA57 experiment at the CERN SPS, with 40 and 158 A GeV/c beam momentum. Results on Λ, Ξ and Ω hyperon yields at mid-rapidity in the most central 53% of Pb–Pb collisions at 40 A GeV/c are presented and compared with those obtained at higher energy, in the same collision centrality range