1,024 research outputs found
Sound detection by the American lobster (Homarus americanus)
No full textAuthor Posting. © Company of Biologists, 2021. This article is posted here by permission of Company of Biologists for personal use, not for redistribution. The definitive version was published in Journal of Experimental Biology 224(6), (2021): jeb240747, https://doi.org/10.1242/jeb.240747.Although many crustaceans produce sounds, their hearing abilities and mechanisms are poorly understood, leaving uncertainties regarding whether or how these animals use sound for acoustic communication. Marine invertebrates lack gas-filled organs required for sound pressure detection, but some of them are known to be sensitive to particle motion. Here, we examined whether the American lobster (Homarus americanus) could detect sound and subsequently sought to discern the auditory mechanisms. Acoustic stimuli responses were measured using auditory evoked potential (AEP) methods. Neurophysiological responses were obtained from the brain using tone pips between 80 and 250 Hz, with best sensitivity at 80–120 Hz. There were no significant differences between the auditory thresholds of males and females. Repeated controls (recordings from deceased lobsters, moving electrodes away from the brain and reducing seawater temperature) indicated the evoked potentials' neuronal origin. In addition, AEP responses were similar before and after antennules (including statocysts) were ablated, demonstrating that the statocysts, a long-proposed auditory structure in crustaceans, are not the sensory organs responsible for lobster sound detection. However, AEPs could be eliminated (or highly reduced) after immobilizing hairfans, which cover much of lobster bodies. These results suggest that these external cuticular hairs are likely to be responsible for sound detection, and imply that hearing is mechanistically possible in a wider array of invertebrates than previously considered. Because the lobsters' hearing range encompasses the fundamental frequency of their buzzing sounds, it is likely that they use sound for intraspecific communication, broadening our understanding of the sensory ecology of this commercially vital species. The lobsters' low-frequency acoustic sensitivity also underscores clear concerns about the potential impacts of anthropogenic noise.This work was supported by a grant from the French Ministry of Higher Education and Research.2022-03-2
Translation Problems of Phraseological Units in "The Autobiography of Quincy Jones"
No full textDarba autore pēta frazeoloģismu tulkošanu grāmatā „Kvinsija Džonsa autobiogrāfija” („The Autobiography of Quincy Jones”).
Tulkošana ir process, kas savieno valodas, cilvēkus un kultūru, un tā ir neatņemama sastāvdaļa informācijas iegūšanai. Tulkošana nav mehāniska darbība, bet gan dzīvs process, kura starpnieks ir tulkotājs. Tulkotāji ik dienas rod atbildes uz dažādām tulkošanas problēmām. Arī darba autore, balstoties uz studiju laikā veiktās tulkošanas prakses pirmo septiņu nodaļu tulkojuma no angļu valodas latviešu valodā, pēta vienu no problēmām. Maģistra darba mērķis ir noteikt frazeoloģismu tulkošanas problēmas Kvinsija Džonsa autobiogrāfijā un izvirzīt iespējamos frazeoloģisko vienību tulkojuma variantus.
Izmantotās metodes ir aprakstošā jeb deskriptīvā metode un analītiskā metode.
Rezultāti parāda, ka kā galveno frazeoloģisko vienību tulkošanas problēmu autore uzskata nespēju piemērot ekvivalentu frazeoloģisko vienību tulkojumā. Autore arī secina, ka daļai frazālo darbības vārduThe author of the present master paper researches translation of phraseological units in “The autobiography of Quincy Jones”.
Translation is a process that connects languages, human and culture as well as it is an integral part for receiving information. Translation is not a mechanical process, but a live process with a translator in between. Translators find answers to numerous translation problems every day. Taking for basis the seven chapter translation of the book from English into Latvian performed during the studies, the author researches one of translation problems. The goal of the paper is to define translation problems of phraseological units in the autobiography of Quincy Jones and to forward possible translation variants of phraseological units.
The methods used in the paper are descriptive and analytical method.
The results show that the one of the main problems in translating phraseological units is non-equivalence for phraseological unit in translation. The author conlud
The number manuscripts with male and female first authors and the gender of the corresponding last author.
No full textN: female first author and female last author = 312, female first author and male last author = 663, male first author and female last author = 255, and male first author and male last author = 1033. Manuscript number does not total 3,348 manuscripts (the number unique manuscripts assigned a handling editor by the JEB) due to authors with unassigned genders.</p
Marking 100 years since Rudolf Höber’s discovery of the insulating envelope surrounding cells and of the beta-dispersion exhibited by tissue
No full text© The Author(s), 2012. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Journal of Electrical Bioimpedance 3 (2012): 74-79, doi:10.5617/jeb.401.Between 1910 and 1913 Rudolf Höber presented proof that the interiors of red blood cells and muscle cells contain conducting electrolytes, and that each conducting core is contained within an insulating membrane. He did this by demonstrating, in a series of remarkable electrical experiments, that the conductivity of compacted cell samples at low frequencies (~150 Hz) was about ten-times less than the value obtained at ~5 MHz. On perforation of the membrane, the low-frequency conductivity increased to a value approaching that exhibited at MHz frequencies. Apart from representing a major milestone in the development of cell biology and electrophysiology, Höber’s work was the first description of what we now call the dielectric b-dispersion exhibited by cell suspensions and fresh tissue
Whistling is metabolically cheap for communicating bottlenose dolphins (Tursiops truncatus)
No full textAuthor Posting. © Company of Biologists, 2019. This article is posted here by permission of Company of Biologists for personal use, not for redistribution. The definitive version was published in Journal of Experimental Biology 223(1), (2019): jeb.212498, doi: 10.1242/jeb.212498.Toothed whales depend on sound for communication and foraging, making them potentially vulnerable to acoustic masking from increasing anthropogenic noise. Masking effects may be ameliorated by higher amplitudes or rates of calling, but such acoustic compensation mechanisms may incur energetic costs if sound production is expensive. The costs of whistling in bottlenose dolphins (Tursiops truncatus) have been reported to be much higher (20% of resting metabolic rate, RMR) than theoretical predictions (0.5–1% of RMR). Here, we address this dichotomy by measuring the change in the resting O2 consumption rate (V̇O2), a proxy for RMR, in three post-absorptive bottlenose dolphins during whistling and silent trials, concurrent with simultaneous measurement of acoustic output using a calibrated hydrophone array. The experimental protocol consisted of a 2-min baseline period to establish RMR, followed by a 2-min voluntary resting surface apnea, with or without whistling as cued by the trainers, and then a 5-min resting period to measure recovery costs. Daily fluctuations in V̇O2 were accounted for by subtracting the baseline RMR from the recovery costs to estimate the cost of apnea with and without whistles relative to RMR. Analysis of 52 sessions containing 1162 whistles showed that whistling did not increase metabolic cost (P>0.1, +4.2±6.9%) as compared with control trials (−0.5±5.9%; means±s.e.m.). Thus, we reject the hypothesis that whistling is costly for bottlenose dolphins, and conclude that vocal adjustments such as the Lombard response to noise do not represent large direct energetic costs for communicating toothed whales.M.P.B. received financial support from a Company of Biologists JEB travel fellowship JEBTF181150, and a grant from the Danish Acoustical Society. F.H.J. was supported by an AIAS-COFUND fellowship from Aarhus Institute of Advanced Studies under the FP7 program of the EU (agreement no. 609033). P.T.M. and recording equipment were funded by a large frame grant from Danish Council for Independent Research | Natural Sciences (Natur og Univers, Det Frie Forskningsråd). A.F. was supported by Fundación Oceanogràfic de la Comunitat Valenciana and Global Diving Research.2020-12-0
Specialization for rapid excitation in fast squid tentacle muscle involves action potentials absent in slow arm muscle
No full textAuthor Posting. © Company of Biologists, 2019. This article is posted here by permission of Company of Biologists for personal use, not for redistribution. The definitive version was published in Journal of Experimental Biology 223(3), (2019): jeb.218081, doi: 10.1242/jeb.218081.An important aspect of the performance of many fast muscle fiber types is rapid excitation. Previous research on the cross-striated muscle fibers responsible for the rapid tentacle strike in squid has revealed the specializations responsible for high shortening velocity, but little is known about excitation of these fibers. Conventional whole-cell patch recordings were made from tentacle fibers and the slower obliquely striated muscle fibers of the arms. The fast-contracting tentacle fibers show an approximately 10-fold greater sodium conductance than that of the arm fibers and, unlike the arm fibers, the tentacle muscle fibers produce action potentials. In situ hybridization using an antisense probe to the voltage-dependent sodium channel present in this squid genus shows prominent expression of sodium channel mRNA in tentacle fibers but undetectable expression in arm fibers. Production of action potentials by tentacle muscle fibers and their absence in arm fibers is likely responsible for the previously reported greater twitch–tetanus ratio in the tentacle versus the arm fibers. During the rapid tentacle strike, a few closely spaced action potentials would result in maximal activation of transverse tentacle muscle. Activation of the slower transverse muscle fibers in the arms would require summation of excitatory postsynaptic potentials over a longer time, allowing the precise modulation of force required for supporting slower movements of the arms.This work was supported by the National Science Foundation (IOS 1557754 to W.F.G. and IOS 0951067 to W.M.K.).2021-01-0
Environmental entrainment demonstrates natural circadian rhythmicity in the cnidarian Nematostella vectensis
No full textAuthor Posting. © Company of Biologists, 2019. This article is posted here by permission of Company of Biologists for personal use, not for redistribution. The definitive version was published in Journal of Experimental Biology 222(21), (2019): jeb.205393, doi:10.1242/jeb.205393.Considerable advances in chronobiology have been made through controlled laboratory studies, but distinct temporal rhythms can emerge under natural environmental conditions. Lab-reared Nematostella vectensis sea anemones exhibit circadian behavioral and physiological rhythms. Given that these anemones inhabit shallow estuarine environments subject to tidal inputs, it was unclear whether circadian rhythmicity would persist following entrainment in natural conditions, or whether circatidal periodicity would predominate. Nematostella were conditioned within a marsh environment, where they experienced strong daily temperature cycles as well as brief tidal flooding around the full and new moons. Upon retrieval, anemones exhibited strong circadian (∼24 h) activity rhythms under a light–dark cycle or continuous darkness, but reduced circadian rhythmicity under continuous light. However, some individuals in each light condition showed circadian rhythmicity, and a few individuals showed circatidal rhythmicity. Consistent with the behavioral studies, a large number of transcripts (1640) exhibited diurnal rhythmicity compared with very few (64) with semidiurnal rhythmicity. Diurnal transcripts included core circadian regulators, and 101 of 434 (23%) genes that were previously found to be upregulated by exposure to ultraviolet radiation. Together, these behavioral and transcriptional studies show that circadian rhythmicity predominates and suggest that solar radiation drives physiological cycles in this sediment-dwelling subtidal animal.A.M.T., R.R.H. and O.L. were supported by the Gordon and Betty Moore Foundation (grant number 4598 to A.M.T. and O.L.). H.E.R. was funded by a Martin Family Fellowship for Sustainability at Massachusetts Institute of Technology and an American dissertation grant from the American Association of University Women.2020-10-1
Ontogenetic variation in the hearing sensitivity of black sea bass (Centropristis striata) and the implications of anthropogenic sound on behavior and communication
No full textAuthor Posting. © Company of Biologists, 2020. This article is posted here by permission of Company of Biologists for personal use, not for redistribution. The definitive version was published in Journal of Experimental Biology (2020): jeb.219683, doi: 10.1242/jeb.219683.Black sea bass (Centropristis striata) is an important fish species in both commercial and recreational fisheries of southern New England and the mid-Atlantic Bight. Due to the intense urbanization of these waters, this species is subject to a wide range of anthropogenic noise pollution. Concerns that C. striata are negatively affected by pile driving and construction noise predominate in areas earmarked for energy development. However, as yet, the hearing range of C. striata is unknown, making it hard to evaluate potential risks. This study is a first step in understanding the effects of anthropogenic noise on C. striata by determining the auditory bandwidth and thresholds of this species using auditory evoked potentials (AEPs), creating pressure and acceleration audiograms. These physiological tests were conducted on wild-caught C. striata in three size/age categories. Results showed that juvenile C. striata significantly had the lowest thresholds, with hearing sensitivity decreasing in the larger size classes. Furthermore, Centropristis striata has fairly sensitive hearing relative to other related species. Preliminary investigations into the mechanisms of their hearing ability were undertaken with gross dissections and an opportunistic micro computed tomography image to address the auditory structures including otoliths and swimbladder morphology. Crucially, the hearing range of C. striata, and their most sensitive frequencies, directly overlap with high-amplitude anthropogenic noise pollution such as shipping and underwater construction.This work was funded by the Bureau of Ocean Energy Management Environmental Studies Program through Interagency Agreement Number M17PG00029 with the U.S. Department of Commerce, National Oceanic and Atmospheric Administration.2021-05-2
Augmenting biologging with supervised machine learning to study in situ behavior of the medusa Chrysaora fuscescens
No full text© The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Fannjiang, C., Mooney, T. A., Cones, S., Mann, D., Shorter, K. A., & Katija, K. Augmenting biologging with supervised machine learning to study in situ behavior of the medusa Chrysaora fuscescens. Journal of Experimental Biology, 222, (2019): jeb.207654, doi:10.1242/jeb.207654.Zooplankton play critical roles in marine ecosystems, yet their fine-scale behavior remains poorly understood because of the difficulty in studying individuals in situ. Here, we combine biologging with supervised machine learning (ML) to propose a pipeline for studying in situ behavior of larger zooplankton such as jellyfish. We deployed the ITAG, a biologging package with high-resolution motion sensors designed for soft-bodied invertebrates, on eight Chrysaora fuscescens in Monterey Bay, using the tether method for retrieval. By analyzing simultaneous video footage of the tagged jellyfish, we developed ML methods to: (1) identify periods of tag data corrupted by the tether method, which may have compromised prior research findings, and (2) classify jellyfish behaviors. Our tools yield characterizations of fine-scale jellyfish activity and orientation over long durations, and we conclude that it is essential to develop behavioral classifiers on in situ rather than laboratory data.This work was supported by the David and Lucile Packard Foundation (to K.K.), the Woods Hole Oceanographic Institution (WHOI) Green Innovation Award (to T.A.M., K.K. and K.A.S.) and National Science Foundation (NSF) DBI collaborative awards (1455593 to T.A.M. and K.A.S.; 1455501 to K.K.). Deposited in PMC for immediate release
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