Ultrasonic signalling by a Bornean frog

Among anuran amphibians, only two species, Odorrana tormota and Huia cavitympanum , are known to possess recessed tympanic membranes. Odorrana tormota is the first non-mammalian vertebrate demonstrated to communicate with ultrasonic frequencies (above 20 kHz), and the frogs' sunken tympana are hypothesized to play a key role in their high-frequency hearing sensitivity. Here we present the first data on the vocalizations of H. cavitympanum . We found that this species emits extraordinarily high-frequency calls, a portion of which are comprised entirely of ultrasound. This represents the first documentation of an anuran species producing purely ultrasonic signals. In addition, the vocal repertoire of H. cavitympanum is highly variable in frequency modulation pattern and spectral composition. The frogs' use of vocal signals with a wide range of dominant frequencies may be a strategy to maximize acoustic energy transmission to both nearby and distant receivers. The convergence of these species' call characteristics should stimulate additional, phylogenetically based studies of other lower vertebrates to provide new insight into the mechanistic and evolutionary foundations of high-frequency hearing in all vertebrate forms.

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Sentence-Based Experience Logging in New Hearing Aid Users

American Journal of Audiology ◽

10.1044/2020_aja-19-00077 ◽

2020 ◽

Vol 29 (3S) ◽

pp. 631-637

Author(s):

Katja Lund ◽

Rodrigo Ordoñez ◽

Jens Bo Nielsen ◽

Dorte Hammershøi

Keyword(s):

Hearing Aid ◽

Patient Experiences ◽

Online Tool ◽

Rehabilitation Process ◽

Hearing Rehabilitation ◽

Clinical Observations ◽

Hearing Aid Use ◽

Wide Range ◽

Insight Into ◽

Shed Light

Purpose The aim of this study was to develop a tool to gain insight into the daily experiences of new hearing aid users and to shed light on aspects of aided performance that may not be unveiled through standard questionnaires. Method The tool is developed based on clinical observations, patient experiences, expert involvement, and existing validated hearing rehabilitation questionnaires. Results An online tool for collecting data related to hearing aid use was developed. The tool is based on 453 prefabricated sentences representing experiences within 13 categories related to hearing aid use. Conclusions The tool has the potential to reflect a wide range of individual experiences with hearing aid use, including auditory and nonauditory aspects. These experiences may hold important knowledge for both the patient and the professional in the hearing rehabilitation process.

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Engineering the Interface between Inorganic Nanoparticles and Biological Systems through Ligand Design

Nanomaterials ◽

10.3390/nano11041001 ◽

2021 ◽

Vol 11 (4) ◽

pp. 1001

Author(s):

Rui Huang ◽

David C. Luther ◽

Xianzhi Zhang ◽

Aarohi Gupta ◽

Samantha A. Tufts ◽

...

Keyword(s):

Organic Synthesis ◽

Molecular Design ◽

Biological Systems ◽

Ligand Design ◽

Inorganic Nanoparticles ◽

Organic Ligands ◽

Biological Applications ◽

Wide Range ◽

Insight Into

Nanoparticles (NPs) provide multipurpose platforms for a wide range of biological applications. These applications are enabled through molecular design of surface coverages, modulating NP interactions with biosystems. In this review, we highlight approaches to functionalize nanoparticles with ”small” organic ligands (Mw < 1000), providing insight into how organic synthesis can be used to engineer NPs for nanobiology and nanomedicine.

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Gas Damping in Capacitive MEMS Transducers in the Free Molecular Flow Regime

Sensors ◽

10.3390/s21072566 ◽

2021 ◽

Vol 21 (7) ◽

pp. 2566

Author(s):

Boris A. Boom ◽

Alessandro Bertolini ◽

Eric Hennes ◽

Johannes F. J. van den Brand

Keyword(s):

Flow Regime ◽

Gas Diffusion ◽

Diffusion Time ◽

Molecular Flow ◽

Free Molecular Flow ◽

Simple Analytical Model ◽

Gas Damping ◽

Wide Range ◽

Capacitive Mems ◽

Insight Into

We present a novel analysis of gas damping in capacitive MEMS transducers that is based on a simple analytical model, assisted by Monte-Carlo simulations performed in Molflow+ to obtain an estimate for the geometry dependent gas diffusion time. This combination provides results with minimal computational expense and through freely available software, as well as insight into how the gas damping depends on the transducer geometry in the molecular flow regime. The results can be used to predict damping for arbitrary gas mixtures. The analysis was verified by experimental results for both air and helium atmospheres and matches these data to within 15% over a wide range of pressures.

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Earless toads sense low frequencies but miss the high notes

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2017.1670 ◽

2017 ◽

Vol 284 (1864) ◽

pp. 20171670 ◽

Cited By ~ 10

Author(s):

Molly C. Womack ◽

Jakob Christensen-Dalsgaard ◽

Luis A. Coloma ◽

Juan C. Chaparro ◽

Kim L. Hoke

Keyword(s):

High Frequency ◽

Species Differences ◽

Low Frequency ◽

Auditory Brainstem ◽

Low Frequencies ◽

Hearing Sensitivity ◽

Sensory Pathways ◽

Airborne Sound ◽

Vibrational Sensitivity ◽

Species Specific

Sensory losses or reductions are frequently attributed to relaxed selection. However, anuran species have lost tympanic middle ears many times, despite anurans' use of acoustic communication and the benefit of middle ears for hearing airborne sound. Here we determine whether pre-existing alternative sensory pathways enable anurans lacking tympanic middle ears (termed earless anurans) to hear airborne sound as well as eared species or to better sense vibrations in the environment. We used auditory brainstem recordings to compare hearing and vibrational sensitivity among 10 species (six eared, four earless) within the Neotropical true toad family (Bufonidae). We found that species lacking middle ears are less sensitive to high-frequency sounds, however, low-frequency hearing and vibrational sensitivity are equivalent between eared and earless species. Furthermore, extratympanic hearing sensitivity varies among earless species, highlighting potential species differences in extratympanic hearing mechanisms. We argue that ancestral bufonids may have sufficient extratympanic hearing and vibrational sensitivity such that earless lineages tolerated the loss of high frequency hearing sensitivity by adopting species-specific behavioural strategies to detect conspecifics, predators and prey.

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Assessing evidence for adaptive evolution in two hearing-related genes important for high-frequency hearing in echolocating mammals

G3 Genes|Genome|Genetics ◽

10.1093/g3journal/jkab069 ◽

2021 ◽

Author(s):

Hui Wang ◽

Hanbo Zhao ◽

Yujia Chu ◽

Jiang Feng ◽

Keping Sun

Keyword(s):

Adaptive Evolution ◽

Hair Cells ◽

High Frequency ◽

Phylogenetic Trees ◽

Outer Hair Cells ◽

Functional Domain ◽

Coding Region ◽

Selective Pressures ◽

Wide Range ◽

Different Parts

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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Prediction of Dead Oil Viscosity: Machine Learning vs. Classical Correlations

Energies ◽

10.3390/en14040930 ◽

2021 ◽

Vol 14 (4) ◽

pp. 930

Author(s):

Fahimeh Hadavimoghaddam ◽

Mehdi Ostadhassan ◽

Ehsan Heidaryan ◽

Mohammad Ali Sadri ◽

Inna Chapanova ◽

...

Keyword(s):

Machine Learning ◽

Viscosity Data ◽

Oil Viscosity ◽

Pvt Data ◽

Proposed Model ◽

Wide Range ◽

Engineering Problems ◽

Functional Forms ◽

Insight Into

Dead oil viscosity is a critical parameter to solve numerous reservoir engineering problems and one of the most unreliable properties to predict with classical black oil correlations. Determination of dead oil viscosity by experiments is expensive and time-consuming, which means developing an accurate and quick prediction model is required. This paper implements six machine learning models: random forest (RF), lightgbm, XGBoost, multilayer perceptron (MLP) neural network, stochastic real-valued (SRV) and SuperLearner to predict dead oil viscosity. More than 2000 pressure–volume–temperature (PVT) data were used for developing and testing these models. A huge range of viscosity data were used, from light intermediate to heavy oil. In this study, we give insight into the performance of different functional forms that have been used in the literature to formulate dead oil viscosity. The results show that the functional form f(γAPI,T), has the best performance, and additional correlating parameters might be unnecessary. Furthermore, SuperLearner outperformed other machine learning (ML) algorithms as well as common correlations that are based on the metric analysis. The SuperLearner model can potentially replace the empirical models for viscosity predictions on a wide range of viscosities (any oil type). Ultimately, the proposed model is capable of simulating the true physical trend of the dead oil viscosity with variations of oil API gravity, temperature and shear rate.

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A new species of Sclerocephalus with a fully ossified endocranium gives insight into braincase evolution in temnospondyls

Journal of Paleontology ◽

10.1017/jpa.2021.51 ◽

2021 ◽

pp. 1-13

Author(s):

Rainer R. Schoch ◽

Gabriela Sobral

Keyword(s):

New Species ◽

Character Evolution ◽

Late Paleozoic ◽

New Taxon ◽

Early Permian ◽

Top Predator ◽

Central European ◽

Wide Range ◽

A New Species ◽

Insight Into

Abstract The late Paleozoic temnospondyl Sclerocephalus formed an aquatic top predator in various central European lakes of the late Carboniferous and early Permian. Despite hundreds of specimens spanning a wide range of sizes, knowledge of the endocranium (braincase and palatoquadrate) remained very insufficient in Sclerocephalus and other stereospondylomorphs because even large skulls had unossified endocrania. A new specimen from a stratigraphically ancient deposit at St. Wendel in southwestern Germany is recognized as representing a new taxon, S. concordiae new species, and reveals a completely ossified endocranium. The sphenethmoid was completely ossified from the basisphenoid to the anterior ethmoid region, co-ossified with the parasphenoid, and the basipterygoid joint was fully established. The pterygoid bears a slender, S-shaped epipterygoid, which formed a robust pillar lateral to the braincase. The massive stapes was firmly sutured to the parasphenoid. In the temnospondyl endocranium, character evolution involved various changes in the epipterygoid region, which evolved distinct morphologies in each of the major clades. UUID: http://zoobank.org/5e6d2078-eacf-4467-84cf-a12efcae7c0b

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An Insight into Saponins from Quinoa (Chenopodium quinoa Willd): A Review

Molecules ◽

10.3390/molecules25051059 ◽

2020 ◽

Vol 25 (5) ◽

pp. 1059 ◽

Cited By ~ 7

Author(s):

Khadija El Hazzam ◽

Jawhar Hafsa ◽

Mansour Sobeh ◽

Manal Mhada ◽

Moha Taourirte ◽

...

Keyword(s):

Heat Treatment ◽

Bitter Taste ◽

Biological Activities ◽

Chenopodium Quinoa ◽

Toxic Effects ◽

Mechanical Abrasion ◽

Important Group ◽

The Past ◽

Wide Range ◽

Insight Into

Saponins are an important group found in Chenopodium quinoa. They represent an obstacle for the use of quinoa as food for humans and animal feeds because of their bitter taste and toxic effects, which necessitates their elimination. Several saponins elimination methods have been examined to leach the saponins from the quinoa seeds; the wet technique remains the most used at both laboratory and industrial levels. Dry methods (heat treatment, extrusion, roasting, or mechanical abrasion) and genetic methods have also been evaluated. The extraction of quinoa saponins can be carried out by several methods; conventional technologies such as maceration and Soxhlet are the most utilized methods. However, recent research has focused on technologies to improve the efficiency of extraction. At least 40 saponin structures from quinoa have been isolated in the past 30 years, the derived molecular entities essentially being phytolaccagenic, oleanolic and serjanic acids, hederagenin, 3β,23,30 trihydroxy olean-12-en-28-oic acid, 3β-hydroxy-27-oxo-olean-12en-28-oic acid, and 3β,23,30 trihydroxy olean-12-en-28-oic acid. These metabolites exhibit a wide range of biological activities, such as molluscicidal, antifungal, anti-inflammatory, hemolytic, and cytotoxic properties.

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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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