Hissing of geese: caller identity encoded in a non-vocal acoustic signal

PeerJ ◽

10.7717/peerj.10197 ◽

2020 ◽

Vol 8 ◽

pp. e10197

Author(s):

Richard Policht ◽

Artur Kowalczyk ◽

Ewa Łukaszewicz ◽

Vlastimil Hart

Keyword(s):

Coefficient Of Variation ◽

Function Analysis ◽

Passerine Bird ◽

Alarm Calls ◽

Expression Recognition ◽

Classification Result ◽

Terrestrial Vertebrates ◽

Predator Response ◽

The Stability ◽

Ground Nesting

Non-vocal, or unvoiced, signals surprisingly have received very little attention until recently especially when compared to other acoustic signals. Some sounds made by terrestrial vertebrates are produced not only by the larynx but also by the syrinx. Furthermore, some birds are known to produce several types of non-syrinx sounds. Besides mechanical sounds produced by feathers, bills and/or wings, sounds can be also produced by constriction, anywhere along the pathway from the lungs to the lips or nostrils (in mammals), or to the bill (in birds), resulting in turbulent, aerodynamic sounds. These noises often emulate whispering, snorting or hissing. Even though hissing sounds have been studied in mammals and reptiles, only a few studies have analyzed hissing sounds in birds. Presently, only the hissing of small, nesting passerines as a defense against their respective predators have been studied. We studied hissing in domestic goose. This bird represents a ground nesting non-passerine bird which frequently produces hissing out of the nest in comparison to passerines producing hissing during nesting in holes e.g., parids. Compared to vocally produced alarm calls, almost nothing is known about how non-vocal hissing sounds potentially encode information about a caller’s identity. Therefore, we aimed to test whether non-vocal air expirations can encode an individual’s identity similar to those sounds generated by the syrinx or the larynx. We analyzed 217 hissing sounds from 22 individual geese. We calculated the Potential for Individual Coding (PIC) comparing the coefficient of variation both within and among individuals. In addition, we conducted a series of 15 a stepwise discriminant function analysis (DFA) models. All 16 acoustic variables showed a higher coefficient of variation among individuals. Twelve DFA models revealed 51.2–54.4% classification result (cross-validated output) and all 15 models showed 60.8–68.2% classification output based on conventional DFA in comparison to a 4.5% success rate when classification by chance. This indicates the stability of the DFA results even when using different combinations of variables. Our findings showed that an individual’s identity could be encoded with respect to the energy distribution at the beginning of a signal and the lowest frequencies. Body weight did not influence an individual’s sound expression. Recognition of hissing mates in dangerous situations could increase the probability of their surviving via a more efficient anti-predator response.

CSIG-22. CANCER-ASSOCIATED MISSENSE SINGLE NUCLEOTIDE VARIANTS REGULATE THE STABILITY AND SUBCELLULAR LOCALIZATION OF NF2/MERLIN

Neuro-Oncology ◽

10.1093/neuonc/noaa215.134 ◽

2020 ◽

Vol 22 (Supplement_2) ◽

pp. ii32-ii32

Author(s):

Charlotte Eaton ◽

Paola Bisignano ◽

David Raleigh

Keyword(s):

Tumor Suppressor ◽

Subcellular Localization ◽

Function Analysis ◽

Single Nucleotide Variants ◽

Single Nucleotide ◽

Ferm Domain ◽

Binding Partners ◽

Subcellular Compartments ◽

The Stability ◽

The Impact

Abstract BACKGROUND Alterations in the NF2 tumor suppressor gene lead to meningiomas and schwannomas, but the tumor suppressor functions of the NF2 gene product, Merlin, are incompletely understood. To address this problem, we performed a structure-function analysis of Merlin by expressing cancer-associated missense single-nucleotide variants (mSNVs) in primary cancer cells for biochemical and cell biology experiments. METHODS All NF2 mSNVs were assembled from cBioPortal and COSMIC, and modelled on the FERM, a-helical, and C-terminal domains of Merlin (PDB 4ZRJ) using comparative structure prediction on the Robetta server and visually inspected using Pymol. mSNV hotspots were defined from sliding windows with at least 10 mutations within 5 residues in either direction. mSNVs from hotspots in meningiomas, schwannomas, or both, were selected for in vitro mechanistic analyses using immunofluorescence and immunoblotting of whole cell, plasma membrane, cytoskeletal, cytoplasmic, nuclear, and chromatin subcellular fractions from M10G meningioma cells and HEI-193 schwannoma cells. RESULTS We identified the following cancer-associated hotspot mSNVs in NF2, which were over-expressed for mechanistic studies: L46R, S156N, W191R, A211D, V219M, R418C and R462K. Endogenous Merlin was detected in all subcellular compartments, but was enriched in the nucleus. L46R and A211D mapped to hydrophobic pockets in the FERM domain, destabilized Merlin, and excluded Merlin from all subcellular compartments except the cytoskeleton. S156N, W191R and V219M also mapped to the FERM domain, but did not affect Merlin stability, and V219M attenuated chromatin localization, suggesting this motif may be involved in binding events that regulate subcellular localization. R418C and R463K mapped to the a-helical domain, but only R418C destabilized Merlin. CONCLUSION Our results suggest that cancer-associated mSNVs inactive the tumor suppressor functions of NF2 by altering the stability, subcellular localization, or binding partners of Merlin. Further work is required to identify and understand the impact of binding partners and subcellular localization on Merlin function.

Optimal use of statistical methods to validate reference gene stability in longitudinal studies

10.1101/545749 ◽

2019 ◽

Cited By ~ 1

Author(s):

Venkat Krishnan Sundaram ◽

Nirmal Kumar Sampathkumar ◽

Charbel Massaad ◽

Julien Grenier

Keyword(s):

Statistical Methods ◽

Reference Gene ◽

Coefficient Of Variation ◽

Reference Genes ◽

Developmental Studies ◽

Variation Analysis ◽

Reference Gene Stability ◽

Statistical Approaches ◽

The Stability ◽

Gene Stability

AbstractMultiple statistical approaches have been proposed to validate reference genes in qPCR assays. However, conflicting results from these statistical methods pose a major hurdle in the choice of the best reference genes. Indeed, as their respective approaches to calculating reference gene stability is different, their suitability has to be tested for a given experimental setting. In this study, the stability of 10 candidate reference genes (Actb, Gapdh, Tbp, Sdha, Pgk1, Ppia, Rpl13a, Hsp60, Mrpl10, Rps26) was assessed using four common statistical approaches (GeNorm, NormFinder, Coefficient of Variation analysis and Pairwise ΔCt method) in a longitudinal setting. We used the development of the cerebellum and the spinal cord of mice as a model to assess the suitability of these statistical methods for reference gene validation. GeNorm and the Pairwise ΔCt were found to be ill suited due to a fundamental assumption in their stability calculations. Whereas, NormFinder and Coefficient of Variation analysis fare better provided they are used complementarily. We therefore devised a workflow combining these two methods for validating reference genes in developmental studies. This workflow proves to be more robust than any of the methods used individually.

Evans function analysis of the stability of non-adiabatic flames

Combustion Theory and Modelling ◽

10.1088/1364-7830/7/3/306 ◽

2003 ◽

Vol 7 (3) ◽

pp. 545-561 ◽

Cited By ~ 10

Author(s):

Peter L Simon ◽

Serafim Kalliadasis ◽

John H Merkin ◽

Stephen K Scott

Keyword(s):

Function Analysis ◽

Evans Function ◽

The Stability

Stability Behavior of Model Reference Adaptive Control Methods in Presence of Aircraft Structural Damage

Volume 9: Mechanical Systems and Control, Parts A, B, and C ◽

10.1115/imece2007-43315 ◽

2007 ◽

Cited By ~ 1

Author(s):

Pascal Nespeca ◽

Nesrin Sarigul-Klijn

Keyword(s):

Adaptive Control ◽

Numerical Study ◽

Function Analysis ◽

Model Reference Adaptive Control ◽

Approximation Technique ◽

Control Methods ◽

Model Reference ◽

Stability Behavior ◽

The Stability ◽

Model Reference Adaptive

Any classical control design starts by first satisfying stability and then looking towards satisfying transient requirements. Similarly, a Model Reference Adaptive Control (MRAC) Method should start with a stability analysis. Lyapunov function analysis is first used to justify the stability of the adaptive scheme. Next, a numerical study is conducted to predict the stability behavior of three different MRAC methods in the presence of large unanticipated changes in the dynamics of an aircraft. The Model reference adaptive control methods studied are: Method:1, an adaptive gain method; Method:2, a Neural Network (NN) approximation technique; and, Method:3, a linear approximation technique. For comparison purposes, the aircraft is assumed to have Linear Time Invariant, LTI dynamics. Each algorithm is given full state feedback, an inaccurate reference model and a poor Linear Quadratic Regulator, LQR design for the true plant. It is seen that when the LQR stabilizes the true plant, the three algorithms all achieve the same steady state error to a step command. Numerical results predict the different types of stability behavior that the algorithms provide. It is seen that the Methods: 2 and 3 can only provide a bounded stability, whereas Method: 1 can provide an asymptotic stability. A robust static controller can satisfy stability, but a robust static controller that accommodates variations in plant dynamics might not always be able to match transient requirements as expected. Although there may be no analytical guarantee from adaptive controllers of transient performance, one might look at anecdotal performances.

Geographic variability in the alarm calls of the European ground squirrel

Current Zoology ◽

10.1093/cz/zoz055 ◽

2019 ◽

Vol 66 (4) ◽

pp. 407-415 ◽

Cited By ~ 2

Author(s):

Irena Schneiderová ◽

Lucie Štefanská ◽

Lukáš Kratochvíl

Keyword(s):

Czech Republic ◽

Ground Squirrel ◽

Function Analysis ◽

Mammalian Species ◽

Ground Squirrels ◽

Alarm Calls ◽

Geographic Variability ◽

The Czech Republic ◽

Spermophilus Citellus ◽

Different Origins

Abstract Geographic variability in vocalizations has been documented in many mammalian species. We examined to what extent it applies to the alarm calls of the European ground squirrel Spermophilus citellus. We recorded the calls of 82 adult individuals from 5 natural colonies in the Czech Republic and 24 adult individuals from an artificial seminatural colony located in a Czech zoo. The founders of this colony originated from 4 different natural colonies in the Czech Republic. Our results showed that there are hardly any differences in the acoustic structure of the alarm calls between male and female European ground squirrels. Discriminant function analysis showed the highest degree of discriminability for the most isolated sites (54–74% of individuals classified correctly), whereas the lowest degree of discriminability was found for 2 interconnected colonies (38–40% individuals classified correctly). Individuals from the artificial seminatural colony were often classified correctly to this colony (58% classified correctly); however, the precision of the classification was comparatively relatively low, that is, many individuals from other colonies were incorrectly classified into this seminatural colony. This likely corresponds to the different origins of its founders. These findings indicate that there is a rather substantial geographic variability in the alarm calls of the European ground squirrel, and our study highlights its possible impact on conservation measures such as establishing artificial colonies or reintroductions.

Structure - function analysis of photosystem II subunit S (PsbS) in vivo

Functional Plant Biology ◽

10.1071/fp02065 ◽

2002 ◽

Vol 29 (10) ◽

pp. 1131 ◽

Cited By ~ 98

Author(s):

Xiao-Ping Li ◽

Alba Phippard ◽

Jae Pasari ◽

Krishna K. Niyogi

Keyword(s):

Amino Acid ◽

Photosystem Ii ◽

Function Analysis ◽

Amino Acid Sequences ◽

Forward Genetics ◽

Photochemical Quenching ◽

Amino Acid Residues ◽

The Stability ◽

Psbs Gene

In land plants, photosystem II subunit S (PsbS) plays a key role in xanthophyll- and pH-dependent non-photochemical quenching (qE) of excess absorbed light energy. Arabidopsis thaliana (L.) Heynh. npq4 mutants are defective in the psbS gene and have impaired qE. Exactly how the PsbS protein is involved in qE is unclear, but it has been proposed that PsbS binds H+ and/or de-epoxidized xanthophylls in excess light as part of the qE mechanism. To identify amino acid residues that are important for PsbS function, we sequenced the psbS gene from eight npq4 point mutant alleles isolated by forward genetics screening, including two new alleles. In the four transmembrane helices of PsbS, several amino acid residues were found to affect the stability and/or function of the protein. By comparing the predicted amino acid sequences of PsbS from several plant species and studying the proposed topological structure of PsbS, eight possible H+-binding amino acid residues on the lumenal side of the protein were identified and then altered by site-directed mutagenesis in vitro. The mutant psbS genes were transformed into npq4-1, a psbS deletion mutant, to test the stability and function of the mutant PsbS proteins in�vivo. The results demonstrate that two conserved, protonatable amino acids, E122 and E226, are especially critical for the function of PsbS.

Reconstitution of the Jasmonate Signaling Pathway in Plant Protoplasts

Cells ◽

10.3390/cells8121532 ◽

2019 ◽

Vol 8 (12) ◽

pp. 1532 ◽

Cited By ~ 1

Author(s):

Ning Li ◽

Joachim F. Uhrig ◽

Corinna Thurow ◽

Li-Jun Huang ◽

Christiane Gatz

Keyword(s):

Signaling Pathway ◽

Function Analysis ◽

Luciferase Reporter ◽

Luciferase Reporter Gene ◽

Protein Levels ◽

Activation Of Transcription ◽

Subsequent Degradation ◽

The Stability ◽

F Box Protein ◽

Ja Signaling

The phytohormone jasmonic acid (JA) plays an important role in various plant developmental processes and environmental adaptations. The JA signaling pathway has been well-elucidated in the reference plant Arabidopsis thaliana. It starts with the perception of the active JA derivative, jasmonoyl-isoleucine (JA-Ile), by the F-box protein COI1 which is part of the E3-ligase SCFCOI1. Binding of JA-Ile enables the interaction between COI1 and JAZ repressor proteins. Subsequent degradation of JAZ proteins leads to the activation of transcription factors like e.g., MYC2. Here we demonstrate that the pathway can be reconstituted in transiently transformed protoplasts. Analysis of the stability of a JAZ1-fLuc fusion protein as a function of COI1 transiently expressed in coi1 protoplasts allows structure function analysis of both JAZs and COI1. Using this system, we found that conserved cysteines in COI1 influence steady state COI1 protein levels. Using a luciferase reporter gene under the control of the JAZ1 promoter enable to address those features of JAZ1 that are required for MYC2 repression. Interestingly, the conserved TIFY-motif previously described to interact with NINJA to recruit the corepressor TOPLESS is not necessary for repression. This result is in favor of the alternative repression mode that proposes a direct competition between repressive JAZs and promotive MEDIATOR25 at MYC2. Finally, using protoplasts from the aos coi1 double mutant, which is deficient in JA synthesis and perception, we provide a system that has the potential to study the activity of different COI1 variants in the presence of different ligands.

The frequency of vocal mimicry associated with danger varies due to proximity to nest and nesting stage in a passerine bird

Behaviour ◽

10.1163/1568539x-00003123 ◽

2014 ◽

Vol 151 (1) ◽

pp. 73-88 ◽

Cited By ~ 6

Author(s):

Eben Goodale ◽

Chaminda P. Ratnayake ◽

Sarath W. Kotagama

Keyword(s):

Sri Lanka ◽

Passerine Bird ◽

Alarm Calls ◽

Mixed Species ◽

Vocal Mimicry ◽

Young Offspring ◽

Mixed Species Flocks ◽

Species Specific ◽

Breeding Seasons ◽

Species Flocks

Several species of birds vocally imitate sounds associated with danger. Two anecdotal studies suggest that such ‘danger mimicry’ increases during nesting, but such a relationship has not been quantitatively demonstrated. Sri Lanka drongos (Dicrurus paradiseus lophorhinus) are known to imitate predators and other species’ mobbing and alarm calls in alarm contexts. Here we investigated whether drongos vary their production of danger mimicry in different nesting stages (building, incubation, nests with hatchlings, fledglings still outside of mixed-species flocks), and when foraging away from young in mixed-species flocks. We recorded drongos over two breeding seasons at 14 different nesting trees, used year-after-year. We found that of all the types of danger mimicry, imitation of predators was the most common and exclusive to drongos that had young offspring. Such predator mimicry was observed at a higher rate during the hatchling and fledgling stages compared to incubation or flocks. Danger mimicry did not, however, increase during this stage in isolation: drongo species-specific alarm calls also increased, and the close connection between these two types of calls did not appear to change. Although it is possible that the association between danger mimicry and species-specific alarm calls could help young birds learn sounds associated with danger, the performance of this behaviour does not seem exclusive enough to interactions between adult drongos and their offspring to meet functional definitions of teaching.

Stability of a Proportional Valve Control System With Backlash and Saturation

ASME/BATH 2013 Symposium on Fluid Power and Motion Control ◽

10.1115/fpmc2013-4502 ◽

2013 ◽

Author(s):

Nader Moustafa ◽

Roger Fales

Keyword(s):

Limit Cycle ◽

Function Analysis ◽

Linear Part ◽

Open Loop ◽

Function Technique ◽

Main Stage ◽

Describing Function ◽

Nonlinear Part ◽

The Stability ◽

Limit Cycle Behavior

In this work, the describing function technique is used to study the stability of a nonlinear system. All of dynamic systems in industrial and fluid power systems are nonlinear and include uncertainties to some degree. Thus, unexpected changes in the stability can be exhibited and can lead these systems to become unstable or exhibit oscillatory behavior. Engineers have developed nonlinear mathematical models to be able to predict whether or not a designed system will be exposed to such an oscillation before considering building and implementing the system. The focus of this study is to predict the existence of nonlinear oscillation behavior in a dynamic system using a simplified approach. A nonlinear model validation of a solenoid operated proportional control valve was performed using open loop testes. The type of two-stage hydraulic valve considered in this research is used to control the velocity of hydraulic cylinders. The pilot valve, which is the focus of this research, is a pressure control 3-way valve. A number of 30 replications of this pilot spool valve were studied and tested experimentally along with a single main stage valve. The model consists of linear and nonlinear parts. The linear part of the model was developed by linearizing the nonlinear governing equations at nominal conditions. The nonlinear part was constructed by analyzing open loop experimental test data. The data showed that two major nonlinearities are found that are key to describing the behavior of the system: saturation of the current input and backlash hysteresis behavior. These nonlinearities were considered to be the cause of limit cycle behavior. Each one of these nonlinearities was represented by its describing function and limit cycles were predicted using the describing function analysis method. In using the describing function method, the complexities of working with the nonlinear physics based model to determine limit cycle behavior were avoided.

Enhancing the resolving power of least‐squares inversion with active constraint balancing

Geophysics ◽

10.1190/1.1581045 ◽

2003 ◽

Vol 68 (3) ◽

pp. 931-941 ◽

Cited By ~ 123

Author(s):

Myeong‐Jong Yi ◽

Jung‐Ho Kim ◽

Seung‐Hwan Chung

Keyword(s):

Least Squares ◽

Function Analysis ◽

Resolution Enhancement ◽

Resolving Power ◽

Stability And Convergence ◽

Lagrangian Multiplier ◽

Active Constraint ◽

Data Set ◽

Resistivity Tomography ◽

The Stability

Most geophysical inverse problems are solved using least‐squares inversion schemes with damping or smoothness constraints to improve stability and convergence rate. Since the Lagrangian multiplier controls resolution and stability of the inverse problem, we always want to use the optimum multiplier, which is not easy to get and is usually obtained by experience or a time‐consuming optimization process. We present a new regularization approach, in which the Lagrangian multiplier is set as a spatial variable at each parameterized block and automatically determined via the parameter resolution matrix and spread function analysis. For highly resolvable parameters, a small value of the Lagrangian multiplier is assigned, and vice versa. This approach, named “active constraint balancing” (ACB), tries to balance the constraints of the least‐squares inversion according to sensitivity for a given problem so that it enhances the resolution as well as the stability of the inversion process. We demonstrate the performance of the ACB by applying it to a two‐dimensional resistivity tomography problem, which results in a remarkable enhancement of the spatial resolution. Enhancement of the resolution is also verified in the application of resistivity tomography to a field data set acquired at a tunnel construction site.