SHORT COMMUNICATION Realistic Assessment of Health Hazards of Chemicals

INTRODUCTION The general public is exposed to a variety of chemicals, including food additives,contaminants, and pesticides. To protect the public from any health hazards associ ated with these chemicals, toxicities are assessed by national regulatory agencies andat an international level by the World Health Organization (WHO) in conjunctionwith the Food and Agriculture Organization of the United Nations (FAO). A briefdescription of the work in this field conducted jointly by WHO and FAO has been

Robot Pheromone Communication Using Vortex Ring Transmission

Unpredictable air movements have proved to be a problem in previous studies investigating robot communication by means of airborne pheromone chemicals. The project described in this paper investigates the use of air vortex rings as a means of carrying pheromone chemicals between transmitting and receiving robots. Sensitivity to chemicals including pheromones released by conspecifics is essential for many aspects of an insect's life. They assist in finding food, locating a mate, avoiding danger and help coordinate the activities of social insects. In the future, autonomous robots will be challenged by many situations similar to those that face insects and other simple creatures. Chemical communication may prove useful for these robots as well. This paper describes the equipment developed for generating and detecting vortex rings. Results of experiments involving location and tracking of a sequence of pheromone vortex rings are also presented.

New avenues for systematically inferring cellcell communication:through single-cell transcriptomics data

For multicellular organisms,cell-cell communication is essential to numerous biological processes.Drawing upon the latest development of single-cell RNA-sequencing(scRNA-seq),high-resolution transcriptomic data have deepened our understanding of cellular phenotype heterogeneity and composition of complex tissues,which enables systematic cell-cell communication studies at a single-cell level.We first summarize a common workflow of cell-cell communication study using scRNA-seq data,which often includes data preparation,construction of communication networks,and result validation.Two common strategies taken to uncover cell-cell communications are reviewed,e.g.,physically vicinal structure-based and ligand-receptor interaction-based one.To conclude,challenges and current applications of cell-cell communication studies at a single-cell resolution are discussed in details and future perspectives are proposed.

Functional characterization of a Niemann-Pick type C2 protein in the parasitoid wasp Micropfitis mediator

Niemann-Pick type C2 （NPC2） is a type of small soluble protein involved in lipid metabolism and triglyceride accumulation in vertebrates and arthropods. Recent stud- ies have determined that NPC2 also participates in chemical communication of arthropods. In this work, two novel NPC2 proteins （MmedNPC2a and MmedNPC2b） in Microplitis mediator were identified. Real-time quantitative PCR （qPCR） analysis revealed that Mmed- NPC2a was expressed higher in the antennae than in other tissues of adult wasps compared with MmedNPC2b. Subsequent immunolocalization results demonstrated that NPC2a was located in the lymph cavities of sensilla placodea. To further explore the binding charac- terization of recombinant MmedNPC2a to 54 candidate odor molecules, a fluorescence binding assay was performed. It was found MmedNPC2a could not bind with selected fatty acids, such as linoleic acid, palmitic acid, stearic acid and octadecenoic acid. How- ever, seven cotton volatiles, 4-ethylbenzaldehyde, 3,4-dimethylbenzaldehyde, fl-ionone, linalool, m-xylene, benzaldehyde and trans-2-hexen-l-al showed certain binding abilities with MmedNPC2a. Moreover, the predicted 3D model of MmedNPC2a was composed of seven r-sheets and three pairs of disulfide bridges. In this model, the key binding residues for oleic acid in CjapNPC2 of Camponotus japonicus, Lue68, Lys69, Lys70, Phe97, Thr103 and Phe127, are replaced with Phe85, Ser86, His87, Leu113, Tyr119 and Ile143 in MmedNPC2a, respectively. We proposed that MmedNPC2a in M. mediator may play roles in perception of plant volatiles.