Design of high-frequency wide-range all digital phase locked loop in 90 nm CMOS

Abstract High-frequency hearing is particularly important for echolocating bats and toothed whales. Previously, studies of the hearing-related genes Prestin, KCNQ4, and TMC1 documented that adaptive evolution of high-frequency hearing has taken place in echolocating bats and toothed whales. In this study, we present two additional candidate hearing-related genes, Shh and SK2, that may also have contributed to the evolution of echolocation in mammals. Shh is a member of the vertebrate Hedgehog gene family and is required in the specification of the mammalian cochlea. SK2 is expressed in both inner and outer hair cells, and it plays an important role in the auditory system. The coding region sequences of Shh and SK2 were obtained from a wide range of mammals with and without echolocating ability. The topologies of phylogenetic trees constructed using Shh and SK2 were different; however, multiple molecular evolutionary analyses showed that those two genes experienced different selective pressures in echolocating bats and toothed whales compared to non-echolocating mammals. In addition, several nominally significant positively selected sites were detected in the non-functional domain of the SK2 gene, indicating that different selective pressures were acting on different parts of the SK2 gene. This study has expanded our knowledge of the adaptive evolution of high-frequency hearing in echolocating mammals.

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Design and Construction of a Low Cost All-Digital Phase Locked Loop Based on Field Programmable Gate Array

Journal of Physics Conference Series ◽

10.1088/1742-6596/1972/1/012054 ◽

2021 ◽

Vol 1972 (1) ◽

pp. 012054

Author(s):

Chunyu Zhang ◽

Shouxiang Wang ◽

Ruxun He ◽

Qianyu Zhao ◽

Kai Wang

Keyword(s):

Field Programmable Gate Array ◽

Low Cost ◽

Phase Locked Loop ◽

Digital Phase ◽

Field Programmable ◽

Gate Array ◽

Design And Construction

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A Reference Oversampling Digital Phase-Locked Loop with -240 dB FOM and -80 dBc Reference Spur

2019 Symposium on VLSI Circuits ◽

10.23919/vlsic.2019.8778010 ◽

2019 ◽

Author(s):

Ji-Hwan Seol ◽

Dennis Sylvester ◽

David Blaauw ◽

Taekwang Jang

Keyword(s):

Phase Locked Loop ◽

Digital Phase ◽

Reference Spur

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Parasites in Antarctic krill guts inferred from DNA sequences

Antarctic Science ◽

10.1017/s0954102018000469 ◽

2019 ◽

Vol 31 (1) ◽

pp. 16-22 ◽

Cited By ~ 2

Author(s):

Alison C. Cleary ◽

Maria C. Casas ◽

Edward G. Durbin ◽

Jaime Gómez-Gutiérrez

Keyword(s):

Dna Sequences ◽

High Frequency ◽

Dna Analysis ◽

Antarctic Krill ◽

Euphausia Superba ◽

Gut Contents ◽

The West ◽

West Antarctic ◽

Wide Range

AbstractThe keystone role of Antarctic krill,Euphausia superbaDana, in Southern Ocean ecosystems, means it is essential to understand the factors controlling their abundance and secondary production. One such factor that remains poorly known is the role of parasites. A recent study of krill diet using DNA analysis of gut contents provided a snapshot of the parasites present within 170E. superbaguts in a small area along the West Antarctic Peninsula. These parasites includedMetschnikowiaspp. fungi,Haptoglossasp. peronosporomycetes,LankesteriaandParalecudinaspp. apicomplexa,Stegophorussp. nematodes, andPseudocolliniaspp. ciliates. Of these parasites,Metschnikowiaspp. fungi andPseudocolliniaspp. ciliates had previously been observed inE. superba, as had other genera of apicomplexans, though notLankesteriaandParalecudina.In contrast, nematodes had previously only been observed in eggs ofE. superba, and there are no literature reports of peronosporomycetes in euphausiids.Pseudocolliniaspp., parasitoids which obligately kill their host, were the most frequently observed infection, with a prevalence of 12%. The wide range of observed parasites and the relatively high frequency of infections suggest parasites may play a more important role than previously acknowledged inE. superbaecology and population dynamics.

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