Beat Pattern Research Articles

Use of optical beating patterns for determining the layer thicknesses and refractive indices of the two-layer structure

Use of optical beating patterns for determining the layer thicknesses and refractive indices of the two-layer structure

Quantum oscillations of pseudomagnetoresistance in tunable tilt-mismatch Dirac-cone junction

This paper presents research on the quantum oscillation of pseudomagnetoresistance (PMR) in tilted Dirac cone material junctions. Dirac cones are linear energy dispersions that arise in materials like graphene, which is a two-dimensional material with unique electronic properties. The presence of a tilted Dirac cone in the energy spectrum of these materials introduces interesting phenomena such as pseudomagnetism and anisotropic quantum transport. By applying strain, we can control the direction of the tilted Dirac cone in graphene and investigate the pseudomagnetotransport properties of this system. Magnetoresistance is a real effect that arises from the Lorentz force acting on the charge carriers, while PMR is a geometric effect that arises from the tilted Dirac cone and the crystal lattice structure of the material. Using computational methods for finite-superlattice materials and the transfer-matrix method, our results show that the quantum beating pattern of PMR is more pronounced with an increased number of barriers. Additionally, we observe that the amplitude and period of the modulation depend on the strength and orientation of the tilted-induced pseudomagnetic field. We demonstrate that the PMR behavior can be tuned and optimized for specific applications, potentially leading to improvements in the design and optimization of graphene-based devices such as sensors, transistors, and quantum computers, which rely on the PMR behavior of graphene.

Human sperm rotate with a conserved direction during free swimming in four dimensions.

Head rotation in human spermatozoa is essential for different swimming modes and fertilisation, as it links the molecular workings of the flagellar beat with sperm motion in three-dimensional (3D) space over time. Determining the direction of head rotation has been hindered by the symmetry and translucent nature of the sperm head, and by the fast 3D motion driven by the helical flagellar beat. Analysis has been mostly restricted to two-dimensional (2D) single focal plane image analysis, which enables tracking of head centre position but not tracking of head rotation. Despite the conserved helical beating of the human sperm flagellum, human sperm head rotation has been reported to be uni- or bi-directional, and even to intermittently change direction in a given cell. Here, we directly measure the head rotation of freely swimming human sperm using multi-plane 4D (3D+t) microscopy and show that: (1) 2D microscopy is unable to distinguish head rotation direction in human spermatozoa; (2) head rotation direction in non-capacitating and capacitating solutions, for both aqueous and viscous media, is counterclockwise (CCW), as seen from head to tail, in all rotating spermatozoa, regardless of the experimental conditions; and (3) head rotation is suppressed in 36% of spermatozoa swimming in non-capacitating viscous medium, although CCW rotation is recovered after incubation in capacitating conditions within the same viscous medium, possibly unveiling an unexplored aspect of the essential need of capacitation for fertilisation. Our observations show that the CCW head rotation in human sperm is conserved. It constitutes a robust and persistent helical driving mechanism that influences sperm navigation in 3D space over time, and thus is of critical importance in cell motility, propulsion of flagellated microorganisms, sperm motility assessments, human reproduction research, and self-organisation of flagellar beating patterns and swimming in 3D space.

High-Speed Video Microscopy of Ependymal Cilia in Brain Organotypic and Cell Culture Models.

The wall of the ventricular system within the neuraxis is lined almost entirely by E1 ependymal cells, each of which projects multiple motile cilia from their apical surface into the cerebrospinal fluid (CSF). This specialized layer of E1 cells constitutes the border between the CSF and the brain interstitial fluid (BIF), and by controlling influx and efflux across the CSF to BIF interface, it is increasingly recognized to play an integral role in modulating and maintaining the brain microenvironment. The motile cilia have been shown to be responsive to changes in the CSF microenvironment, and while the physiological role of this mechanism remains incompletely understood, manipulating this control mechanism may influence the brain microenvironment potentially opening a new frontier in therapeutic intervention.In this paper, we describe our techniques for preparing organotypic slices from the murine brain parenchyma and establishing cell cultures of multiciliated ependymal cells from mouse and rat neonatal brain tissue. Our methodology generates a functional readout of ciliary function, specifically high-speed video microscopy (HSVM) enables the quantification of ciliary beat frequency (CBF), and characterization of ciliary beat pattern.

Temporal Stability of Ciliary Beating Post Nasal Brushing, Modulated by Storage Temperature.

Primary ciliary dyskinesia is a heterogeneous, inherited motile ciliopathy in which respiratory cilia beat abnormally, and some ultrastructural ciliary defects and specific genetic mutations have been associated with particular ciliary beating alterations. Ciliary beating can be evaluated using digital high-speed videomicroscopy (DHSV). However, normal reference values, essential to assess ciliary beating in patients referred for a PCD diagnostic, vary between centres, as minor variations in protocols might influence ciliary beating. Consequently, establishment of normal values is essential for each PCD diagnostic centre. We aimed to evaluate whether delay after sampling, and temperature for conservation of respiratory ciliated samples, might modify assessments of ciliary beating. In total, 37 healthy nasal brushing samples of respiratory ciliated epithelia were collected. Video sequences were recorded at 37 °C immediately using DHSV. Then, the samples were divided and conserved at 4 °C or at room temperature (RT). Ciliated beating edges were then recorded at 37 °C, at 3 h and at 9 h post sampling. In six samples, recordings were continued up to 72 h after sampling. Ciliary beating was assessed manually by ciliary beat frequency (CBFM) and ciliary beat pattern (CBP). A semi-automatic software was used for quantitative analysis. Both CBF and CBP evaluated manually and by a semi-automated method were stable 9 h after sampling. CBFM was higher when evaluated using samples stored at RT than at 4 °C. CBP and the semi-automated evaluation of ciliary beating were not affected by storage temperature. When establishing normal references values, ciliary beating can be evaluated at 37 °C up to 9 h after nasal brushing, but the storage temperature modifies ciliary beating and needs to be controlled.

Transient dynamics in mode-locked all-PM Er-doped fiber laser with NALM

In this study, we utilized the Time-Stretch Dispersive Fourier Transform (TS-DFT) method to explore rapid transient states in both time and frequency domains of an all-polarization-maintaining dispersion-managed figure-eight mode-locked laser with Nonlinear Amplifying Loop Mirror (NALM). We detail the different stages of build-up dynamics at varying pump powers, encompassing the Q-switching (QS) stage, transient single pulse formation, pulsation beating patterns, bound states, and the final transition to a single pulse state. Our findings reveal that the mode-locked bound state regime emerges from a single pulse stage following QS, different from previously reported directly resulting from QS pulses or relaxation oscillations. In a novel contribution to the field, we have experimentally demonstrated the transient single pulse stage of build-up dynamics and compared it with the fundamental mode-locked single pulse.

Nonlinearities of the gap resonance for a free-heaving moonpool: Higher-order harmonics and natural frequency component

The piston-mode gap resonance of a free-heaving moonpool was investigated in a two-dimensional numerical wave tank based on a Constrained Interpolation Profile (CIP) method. The wave elevation at the narrow gap, the moonpool's heave response, and wave loads on the free-heaving moonpool were all specifically examined in the current study, which was primarily focused on the higher-order harmonics of the gap resonance for the free-heaving moonpool against various gap widths and body drafts. The flow pattern around the entrance of the gap of the free-heaving moonpool was identified at the typical resonant frequencies. The frequency range of the beat pattern for the wave elevation at the gap was initially suggested. Furthermore, the natural frequency component (NFC) was observed from the interesting beat patterns, and the NFC-based approach was proposed as a straightforward way to forecast the resonant frequency of the free-heaving moonpool. Numerical studies showed that the quadratic wave excitation (QWE) driven gap resonances were recorded for both the fixed and the free-heaving moonpools versus regular waves. The resonance frequency of the free-heaving moonpool can be directly, precisely, and rapidly estimated using the suggested NFC-based approach. Finally, four frequency zones were proposed to differentiate the various gap resonances for the free-heaving moonpool based on distinct hydrodynamic characteristics of the wave elevation at gap.

The Cilialyzer – A freely available open-source software for the analysis of mucociliary activity in respiratory cells

Background and ObjectivePrimary ciliary dyskinesia (PCD) is a rare genetic disorder causing a defective ciliary structure, which predominantly leads to an impaired mucociliary clearance and associated airway disease. As there is currently no single diagnostic gold standard test, PCD is diagnosed by a combination of several methods comprising genetic testing and the examination of the ciliary structure and function. Among the approved diagnostic methods, only high-speed video microscopy (HSVM) allows to directly observe the ciliary motion and therefore, to directly assess ciliary function. In the present work, we present our recently developed freely available open-source software – termed “Cilialyzer”, which has been specifically designed to support and facilitate the analysis of the mucociliary activity in respiratory epithelial cells captured by high-speed video microscopy. MethodsIn its current state, the Cilialyzer software enables clinical PCD analysts to load, preprocess and replay recorded image sequences as well as videos with a feature-rich replaying module facilitating the commonly performed qualitative visual assessment of ciliary function (including the assessment of the ciliary beat pattern). The image processing methods made accessible through an intuitive user interface allow clinical specialists to comfortably compute the ciliary beating frequency (CBF), the activity map and the “frequency correlation length” – an observable getting newly introduced. Furthermore, the Cilialyzer contains a simple-to-use particle tracking interface to determine the mucociliary transport speed. ResultsCilialyzer is fully written in the Python programming language and freely available under the terms of the MIT license. The proper functioning of the computational analysis methods constituting the Cilialyzer software is demonstrated by using simulated and representative sample data from clinical practice. Additionally, the software was used to analyze high-speed videos showing samples obtained from healthy controls and genetically confirmed PCD cases (DNAI1 and DNAH11 mutations) to show its clinical applicability. ConclusionsCilialyzer serves as a useful clinical tool for PCD analysts and provides new quantitative information awaiting to be clinically evaluated using cohorts of PCD. As Cilialyzer is freely available under the terms of a permissive open-source license, it serves as a ground frame for further development of computational methods aiming at the quantification and automation of the analysis of mucociliary activity captured by HSVM.

MODELING AND SYNTHESIS OF THE WISTAR RAT ELECTROCARDIOGRAM

In this work, we present a synthesizer of electrocardiographic signals of the experimental model of the Wistar rat. Firstly, we modeled the P, R, and S waves using Gaussian functions, while for the T-wave, we used a Gumbel function. We validated the proposed model using a Wistar rat electrocardiogram database, which contains 41 animals with 62,907 beats. Model global performance was CC (correlation [Formula: see text], and RE (relative [Formula: see text]. We also propose a transformation that allows the aforementioned model to be built from the standard ECG parameters, such as RR interval, P wave duration, PR interval, RS interval, QT interval, and P, R, S, and T wave amplitudes. In all cases, the correlation coefficients obtained were greater than 0.966, while the mean of the absolute errors of the parameters did not exceed 6[Formula: see text]ms and 30[Formula: see text][Formula: see text]V. Also, we have developed software that integrates the proposed model and the transformation. We used a system of coupled differential equations to synthesize several beats based on one cardiac beat pattern with the possibility of entering variability in the ECG parameters and adding noise to give realism to the electrocardiographic signals. In conclusion, we developed a synthesizer of Wistar rats ECG useful for several applications, such as delineation and segmentation, training and testing of automatic algorithms to detect and monitor, as well as novel filtering methods of these types of ECG signals.

CCDC176 stabilizes microtubule doublets 1 and 9 to ensure proper sperm movement

The molecular mechanism underlying asymmetric axonemal complexes in sperm flagella is still largely unknown. Here, we showed that the knockout of the coiled-coil domain-containing 176 (CCDC176) in mice led to male infertility due to decreased sperm motility. Ccdc176 knockout specifically destabilized microtubule doublets (MTDs) 1 and 9 during sperm maturation in the corpus epididymis. Single-sperm immunofluorescence showed that most CCDC176 was distributed along the axoneme, and further super-resolution imaging revealed that CCDC176 is asymmetrically localized in the sperm axoneme. CCDC176 could cooperate with microtubule and radial spoke proteins to stabilize MTDs 1 and 9, and its knockout results in the destabilization of some proteins in sperm flagella. Furthermore, as predicted by the sperm multibody dynamics (MBD) model, we found that MTDs 1 and 9 jutted out from the sperm flagellum annulus region in Ccdc176-/- spermatozoa, and these flagellar defects alter sperm flagellar beat patterns and swimming paths, potentially owing to the reduction and disequilibration of bending torque on the central pair. These results demonstrate that CCDC176 specifically stabilizes MTDs 1 and 9 in the sperm flagellum to ensure proper sperm movement for fertilization.

MBFRDH: Design of a Multimodal Bioinspired Feature Representation Deep Learning Model for Identification of Heart-Diseases

Electrocardiograms (ECGs) are generated by checking different beating patterns of heart, and are widely used for identification of multiple heart-related issues. Existing deep learning models that are proposed for ECG analysis are either highly complex, or showcase lower scalability when applied to clinical scans. To overcome these issues, this text proposes design of a novel multimodal bioinspired feature representation deep learning model for identification of heart-diseases. The proposed model initially collects large-scale ECG datasets, and extracts Fourier, Cosine, iVector, Gabor, and Wavelet components. These components are given to a Grey Wolf Optimization (GWO) based feature selection model, which assists in identification of high-inter-class variance feature sets. This is done via modelling a variance-based fitness function and fusing it with an Iterative Learning Model (ILM) that use feedback-accuracy levels for optimization of selected feature sets. The extracted features are used to incrementally train a custom 1D Binary-Augmented Convolutional Neural Network (1D BACNN) that can be trained for multiclass scenarios. The BACNN Model is trained individually for each of the heart diseases. Each BACNN categorizes input ECG samples between ‘Normal’, and ‘Heart-Disease’ categories. Due to use of this binary-type classification, the proposed model is able to achieve a consistent 99.9% accuracy for multiple heart disease sets, which is found to be higher than most of the existing multiclass techniques. The model was tested for Angina, Arrhythmia, Valve disease, and Congenital heart conditions, and was observed to achieve 3.5% higher precision, 4.9% higher accuracy, with 1.2% increase is computational delay, which makes it highly suitable for real-time clinical use cases.

Analysis Of the Structure of Music Penanian Dolo Mesa'ri Tendan Lamatoto' Song

Penanian Dolo This is a spiritual song brought by evangelists from the Netherlands along with the Dutch colonial events in Tana Toraja. Penanian Dolo is a song or song that was originally used in the liturgy of Christian worship in Tana Toraja. Over time, Penanian Dolo was used by the people of Gandangbatu in the procession of carrying the corpse (Ma'bulle Tomate).This study aims to determine the form and structure of Penanian Dolo music, Mesa'ri Tendan Lamatoto'. The research method used in this research is qualitative research using sociology and musicology approaches. The results of the study show that Penanian Dolo music, the song Mesa'ri Tendan Lamatoto'is a one-part song form with a total of 8 bars composed of one sentence/period. The song Mesa'ri Tendan Lamatoto' has two clauses, namely interrogative sentences/antecedent phrases (bars 1 – 4) and answer sentences/consequences phrases (bars 5 – 8). Each has the same number of bars but in the consequence phrase motif there are sentence pieces that are not the same length, in other words, they are not symmetrical. This can happen because the division of motifs must pay attention to the integrity of a sentence because the unity of the sentence is more important than the importance of each tone. The motif of the song begins with a tonic chord and ends with a dominant chord to a tonic chord (perfect cadences). The development of dominant motifs uses repetition techniques. The rhythm used in the song Mesa'ri Tendan Lamatoto' uses three types of note values, namely not , notes ¼ and notes 1/8 . The measure or beat pattern used in Mesa'ri Tendan Lamatoto's song uses 4/4 measure, which means that there are four quarter notes in one measure. The tempo used in Mesa'ri Tendan Lamatoto song is moderato which means moderate with a speed of 92-104 beats per minute. The melody used in the Penanian Dolo song as a whole uses diatonic scales. On the other hand, the lyrics in Mesa'ri Tendan Lamatoto' contain aspects of worship and surrender to the almighty. The melody used in the song Penanian Dolo as a whole uses a diatonic scale. On the other hand, the poems in the song Mesa'ri Tendan Lamatoto' contain aspects of worship and submission to the almighty. The melody used in the Penanian Dolo song as a whole uses diatonic scales. On the other hand, the lyrics in Mesa'ri Tendan Lamatoto' contain aspects of worship and surrender to the almighty.

Artificial Cilia–Bridging the Gap with Nature

AbstractHuman ingenuity has found a multitude of ways to manipulate fluids across different applications. However, the fundamentals of fluid propulsion change when moving from the macro‐ to the microscale. Viscous forces dominate inertial forces rendering successful methods at the macroscale ineffective for microscale fluid propulsion. Nature however has found a solution; microscopic active organelles protruding from cells that feature intricate beating patterns: cilia. Cilia succeed in propelling fluids at small dimensions; hence they have served as a source of inspiration for microfluidic applications. Mimicking biological cilia however remains challenging due to their small size and the required kinematic complexity. Recent advances have pushed artificial cilia technology forward, yet discrepancies with natural cilia still exists. This study identifies this gap by analyzing artificial cilia technology and benchmarking them to natural cilia, to pinpoint the remaining design and manufacturing challenges that lay at the basis of the disparity with nature.

Focus of alignment and performance accuracy among wind band musicians in situations of audio-visual asynchrony

Ensemble musicians must navigate a complex sensory environment to produce cohesive performances. The purpose of this study was to examine pulse alignment among performers of different experience levels facing increasingly asynchronous auditory and visual information. Musicians ( N = 51) who were current members of large instrumental ensembles watched a video of a conductor outlining a 4/4 pattern while hearing a multivoiced instrumental ensemble soundtrack and were asked to tap the pulse on a tablet-based pad. Each of nine examples was presented in one of three experimental formats: control (steady audio and video), audio (ensemble) accelerating/video (conductor beat pattern) decelerating, and video accelerating/audio decelerating. Rate of pulse change was ±7.5% with initial tempos of 108, 127, and 146 bpm. Data consisted of (1) deviations (ms) from a consistent IOI (steady pulse) and (2) mean deviations from audio (ensemble) or video (conductor) pulse. In the asynchronous conditions, participants broadly adhered to auditory or visual information rather than to a steady rate of pulse. There was no significant difference between information stream preference. Experience was a significant factor in audio information deviations; more experienced performers found audio information to be a more salient reference point, consistent with results reported for less contextualized timekeeping tasks.

Injectable contraceptive Depo-Provera induces erratic beating patterns in patient-specific induced pluripotent stem cell–derived cardiomyocytes with long QT syndrome type 2

Long QT syndrome type 2 (LQT2) is caused by pathogenic variants in KCNH2. LQT2 may manifest as QT prolongation on an electrocardiogram and present with arrhythmic syncope/seizures and sudden cardiac arrest/death. Progestin-based oral contraceptives may increase the risk of LQT2-triggered cardiac events in women. We previously reported on a woman with LQT2 and recurrent cardiac events temporally related and attributed to the progestin-based contraceptive medroxyprogesterone acetate ("Depo-Provera" [Depo] MilliporeSigma, Catalog# 1378001, St. Louis, MO). The purpose of this study was to evaluate the arrhythmic risk of Depo in a patient-specific induced pluripotent stem cell-derived cardiomyocyte (iPSC-CM) model of LQT2. An iPSC-CM line was generated from a 40-year-old woman with p.G1006Afs∗49-KCNH2. A CRISPR/Cas9 gene-edited/variant-corrected isogenic control iPSC-CM line was generated. FluoVolt (Invitrogen, F10488, Waltham, MA) was used to measure the action potential duration after treatment with 10 μM Depo. Erratic beating patterns characterized as alternating spike amplitudes, alternans, or early afterdepolarization-like phenomena were assessed using multielectrode array (MEA) after 10 μM Depo, 1 μM isoproterenol (ISO), or combined Depo + ISO treatment. Depo treatment shortened the action potential duration at 90% repolarization of G1006Afs∗49 iPSC-CMs from 394 ± 10 to 303 ± 10 ms (P < .0001). Combined Depo + ISO treatment increased the percentage of electrodes displaying erratic beating in G1006Afs∗49 iPSC-CMs (baseline: 18% ± 5% vs Depo + ISO: 54% ± 5%; P < .0001) but not in isogenic control iPSC-CMs (baseline: 0% ± 0% vs Depo + ISO: 10% ± 3%; P = .9659). This cell study provides a potential mechanism for the patient's clinically documented Depo-associated episodes of recurrent ventricular fibrillation. This invitro data should prompt a large-scale clinical assessment of Depo's potential proarrhythmic effect in women with LQT2.

Axonemal regulation by curvature explains sperm flagellar waveform modulation.

Flagellar motility is critical to natural and many forms of assisted reproduction. Rhythmic beating and wave propagation by the flagellum propels sperm through fluid and enables modulation between penetrative progressive motion, activated side-to-side yaw and hyperactivated motility associated with detachment from epithelial binding. These motility changes occur in response to the properties of the surrounding fluid environment, biochemical activation state, and physiological ligands, however, a parsimonious mechanistic explanation of flagellar beat generation that can explain motility modulation is lacking. In this paper, we present the Axonemal Regulation of Curvature, Hysteretic model, a curvature control-type theory based on switching of active moment by local curvature, embedded within a geometrically nonlinear elastic model of the flagellum exhibiting planar flagellar beats, together with nonlocal viscous fluid dynamics. The biophysical system is parameterized completely by four dimensionless parameter groupings. The effect of parameter variation is explored through computational simulation, revealing beat patterns that are qualitatively representative of penetrative (straight progressive), activated (highly yawing) and hyperactivated (nonprogressive) modes. Analysis of the flagellar limit cycles and associated swimming velocity reveals a cusp catastrophe between progressive and nonprogressive modes, and hysteresis in the response to changes in critical curvature parameter. Quantitative comparison to experimental data on human sperm exhibiting typical penetrative, activated and hyperactivated beats shows a good fit to the time-average absolute curvature profile along the flagellum, providing evidence that the model is capable of providing a framework for quantitative interpretation of imaging data.

Fishing for complements with chord, scale, and rhythm nets

The aim of this paper is to argue that complementation is an operation similarly fundamental to music theory as transposition and inversion. We focus on studying the chromatic complement mapping that translates diatonic seventh chords into 8-note scales which can also be interpreted as rhythmic beat patterns. Such complements of diatonic seventh chords are of particular importance since they correspond to the scales popularized by the Jazz theorist Barry Harris, as well as to rhythms used in African drum music and Steve Reich's Clapping Music. Our approach enables a systematic study of these scales and rhythms using established theories of efficient voice leading and generalized diatonic scales and chords, in particular the theory of second-order maximally even sets. The main contributions of this research are (1) to explicate the correspondence between voice leadings and rhythmic transformations, (2) to systematize the family of Barry Harris scales, and (3) to describe classes of voice leadings between chords of different cardinality that are invariant under complementation.

Helical bending waves superimposed on large helical waves of an extremely long sperm flagellum of Drosophila melanogaster

Insect sperm flagella show wide variety of their internal structures and beating patterns. Accurate description of the features will provide important information for understanding the mechanism of axonemal structure and the corresponding bending wave generation. Here, we focus on spermatozoa of Drosophila melanogaster, which has an extremely long flagellum with a length of 2 millimeters. Its internal structure, axoneme has 9+9+2 architecture, distinct from conventional 9+2 axoneme. Unlike axonemes from the flagella of Chlamydomonas or sea urchins, the constituent proteins of axonemes of Drosophila sperm have not been well characterized. Nevertheless, Drosophila axonemes have many advantages over axonemes from other sources. (1) Drosophila is one of the best-established laboratory animals. It has a short life cycle and is easy to breed. (2) Complete genome information is available. (3) A vast number of mutants have been created, natural or transgenic, and many of them are available from stock centers worldwide. Taking these advantages, here, we isolated spermatozoa from the testes and recorded their movement with a high-speed camera. The spermatozoon swims in a spiral pathway in the radius of a few hundred micrometers, and the beating wave consists of minor waves (20-30 Hz, wavelength = ca. 30 μm) superimposed on major waves. Although its physiological significance is unclear, the double-wave nature of the beating pattern could be related to the 9 + 9 + 2 architecture. When combined with the genetic resource of Drosophila, the precise observation will provide a powerful clue for studying the structure-function relationship of eukaryotic flagella in general. This work was supported by JSPS KAKENHI, 26440089 and 17K07376 to K.O., JP16H06280, the Takeda Science Foundation (K.O.) and Hyogo Science and Technology Association (K.O.).

Methods of Mode Generation Inside Hollow Core Photonic Crystal Fibers

Microspheres trapped inside Hollow Core Photonic Crystal Fibers (HCPCF) could provide a way to monitor the temperature in hydrogen combustors, thereby helping to provide a warning system for flashback and thermoacoustic oscillations that can lead to expensive combustor damage. The temperature of a particle trapped in a HCPCF may be extracted by the analysis of the particles' motion, which can be in turn controlled by opportune manipulation of the spatial intensity profile of the light in HCPCF. To this aim, an intermodal beating intensity pattern may be created inside the HCPCF using a mixture of LP01 and LP11 modes. In this work, methods of generating the optical modes, which involve the use of spatial light shaping techniques, are presented and analysed. This is an important step to producing a controllable intermodal beating pattern.

Behavioral assessment of Tambaqui juveniles (Colossoma macropomum) exposed to different ambient colors and social stress

Animal welfare regards the quality of life and the environment in which animals live or are exposed. Hence the importance of studies assessing the environmental influence on the biology and behavior of fishes from the Colossoma macropomum species, considering their higher potential for fish-farming and as a test organism in scientific research. This study aimed to assess, in a controlled environment, the behavioral changes expressed by juveniles from the Colossoma macropomum species exposed to different ambient colors or social situations. The results did not show an influence from the different ambient colors or social situations on fish distribution in the water column. The color pattern showed dark tones in black- and blue-colored environments, and light tones in white-colored environments or with the presence of a mirror. The time of locomotor activity/frequency did not change in any of the treatments of exposure to environments with colors and a mirror. Moreover, the fishes remained with folded fins and a straight posture, maintaining a pattern of rhythmic operculum beating in a normal frequency range described for the species. This suggests that animal welfare did not change in any of the situations tested and that there was a pattern of adaptive response to the type of environment.