Tonotopically Arranged Traveling Waves in the Miniature Hearing Organ of Bushcrickets

Place based frequency discrimination (tonotopy) is a fundamental property of the coiled mammalian cochlea. Sound vibrations mechanically conducted to the hearing organ manifest themselves into slow moving waves that travel along the length of the organ, also referred to as traveling waves. These traveling waves form the basis of the tonotopic frequency representation in the inner ear of mammals. However, so far, due to the secure housing of the inner ear, these waves only could be measured partially over small accessible regions of the inner ear in a living animal. Here, we demonstrate the existence of tonotopically ordered traveling waves covering most of the length of a miniature hearing organ in the leg of bushcrickets in vivo using laser Doppler vibrometery. The organ is only 1 mm long and its geometry allowed us to investigate almost the entire length with a wide range of stimuli (6 to 60 kHz). The tonotopic location of the traveling wave peak was exponentially related to stimulus frequency. The traveling wave propagated along the hearing organ from the distal (high frequency) to the proximal (low frequency) part of the leg, which is opposite to the propagation direction of incoming sound waves. In addition, we observed a non-linear compression of the velocity response to varying sound pressure levels. The waves are based on the delicate micromechanics of cellular structures different to those of mammals. Hence place based frequency discrimination by traveling waves is a physical phenomenon that presumably evolved in mammals and bushcrickets independently

2020 taxonomic update for phylum Negarnaviricota (Riboviria: Orthornavirae), including the large orders Bunyavirales and Mononegavirales

In March 2020, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. At the genus rank, 20 new genera were added, two were deleted, one was moved, and three were renamed. At the species rank, 160 species were added, four were deleted, ten were moved and renamed, and 30 species were renamed. This article presents the updated taxonomy of Negarnaviricota as now accepted by the ICTV. © 2020, This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply

Amino acid and fatty acid levels affect hepatic phosphorus metabolite content in metabolically healthy humans

Objective: Hepatic energy metabolism negatively relates to insulin resistance and liver fat content in patients with type 2 diabetes, but its role inmetabolically healthy humans is unclear.Wehypothesized that intrahepatocellular g-Adenosine triphosphate (gATP) and inorganic phosphate (Pi) concentrations exhibit similar associations with insulin sensitivity in nondiabetic, nonobese volunteers. Design:Atotal of 76 participantsunderwent a four-point sampling, 75-goralglucose tolerance test (OGTT), as well as in vivo 31P/1Hmagnetic resonance spectroscopy. In 62 of them, targeted plasmametabolomic profiling was performed. Pearson correlation analyses were performed for the dependent variables gATP and Pi. Results: Adjusted for age, sex, and body mass index (BMI), hepatic gATP and Pi related to 2-hour OGTT glucose (r = 0.25 and r = 0.27, both P<0.05), and Pi further associated with nonesterified fatty acids (NEFAs; r = 0.28, P < 0.05). However, neither gATP nor Pi correlated with several measures of insulin sensitivity. Hepatic gATP correlated with circulating leucine (r = 0.42, P< 0.001) and Pi with C16:1 fatty acids palmitoleic acid and C16:1w5 (r = 0.28 and 0.30, respectively, P< 0.01), as well as with d-9-desaturase index (r = 0.33, P <0.05). Only the association of gATP with leucine remained important after correction for multiple testing. Leucine and palmitoleic acid, together with age, sex, and BMI, accounted for 26% and for 15% of the variabilities in gATP and Pi, respectively. Conclusions: Specific circulating amino acids and NEFAs, but notmeasures of insulin sensitivity, partly affect hepatic phosphorus metabolites, suggesting mutual interaction between hepatic energy metabolism and circulating metabolites in nondiabetic humans. Copyright © 2018 Endocrine Society