How a low-frequency vibration induces sexual behaviour in a mouse model of the hemisphere, and how genome editing can help rice plants more water efficient

Researchers have been able to identify how certain nerve-cell structures on the penis and clitoris are activated. There is little known about what happens to the corpuscles if they are touched, or their role in sex. A team of people working in mice have discovered that low-frequency vibrates cause sexual behaviours in both males and females. The researchers hope that their work will uncover the Neurological basis behind sexual problems.

The identity of a mystery object and how genome editing can make rice plants more water- efficient are under scrutiny by Astronomers.

Fish motion analysis using PIVlab80 for the measurement of the motion of inner structures of a submerged fish using an external speaker in a DAQ card

The fish was stimulated by using two facing speakers. The water got to the parts of the diaphragms that were exposed. The speakers were located about 1.3 cm away from the fish. They were driven using a DAQ card (National Instruments USB-6211), connected through audio amplifiers (Kemo M031N, 3.5 W). The fish position has a pressure of approximately 1 Pa and particle motion of around 8 MM s1, which are in line with the expected amplitude relationship between pressure and motion.

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We used the tool PIVlab80, originally developed to measure the motion of flowing particles, to analyse the motion of the inner structures of the fish. Essentially, the particle displacement is assessed by cross-correlating subregions with decreasing sizes of consecutive images (Extended Data Fig. 10b(v)). The contrast of the reflectance images was enhanced before the displacement analysis, and the results were curated in post-processing by removing outliers and interpolating detection gaps.

To reconstruct amplitudes and relative phases of sinusoidal object motion, we needed to measure each pixel under more than two different phases according to the Shannon–Nyquist sampling theorem. As noise can influence this measurement, we used four phase steps here, ensuring proper phase reconstruction while keeping acquisition sessions reasonably short.

Long-term acoustic resonance vibrometry with a laser-scanning microscope: principle, data, and experiments in fish microscopy

The principle of the laser-scanning vibrometric measurement is illustrated in Fig. Fig. 10b has 3b and extended data. The sample (Extended Data Fig. 10b(i)) was stimulated with an acoustic sinusoidal wave at frequency ({f}{{\rm{stim}}}), and imaged with a laser-scanning microscope with a line rate ({f}{{\rm{scan}}}) (Extended Data Fig. 10b(ii)).

Fish were anaesthetized in 120 mg l−1 fish water-buffered MS-222. They were subsequently placed on a preformed agarose mould, which allowed the gill covers to move freely, and immobilized with 2% low-melting-point agarose (melting point 25 °C). The aerated aquarium water was delivered through a glass capillary.

The confocal microscope was built on top of a two-photon microscope. The illumination source is a Ti:sapphire laser. There is a beam passing through a 90:10 beam splitter before entering a microscope. The light back-scattered by the fish inner structures was descanned, reflected by the 90:10 beam splitter, and then focused by a lens (f = 50 mm) into a single-mode fibre (core diameter: 25 µm, numerical aperture: 0.1) acting as a confocal pinhole. The microscope was controlled by custom-written software (https://github.com/danionella/lsmaq).

The data in Figs. 1–4 and Extended Data Figs. 4–7 and 12a stem from 65 untreated fish (3,798 playbacks, 1,415 startles, about 37% startles). For each stimulus, we indicated the number of fish that responded with at least one startle. The same experiment, also comprising 12 sound configurations, was repeated with 74 lateral line-ablated fish (Extended Data Figs. 7 and 9; 2013 playbacks, 910 startles, 45% startles). An experiment was performed in the dark in 43 fish to test a segment of four sound configurations.

A 12-month-old male D. cerebrum was put down and fixed with 4% paraformaldehyde inPBS at night. The next day, the fish was washed for 15 min in PBS before being stained with 5% phosphomolybdic acid (Sigma Aldrich) solution in PBS at 4 °C overnight. After staining, the fish was washed in PBS for 15 min before embedding in 1% PBS-buffered agarose inside a cryo tube. The micro-CT scan was carried out at the ANATOMIX beamline at SOLEIL synchrotron by XPLORAYTION. The sample was placed into the white X-ray beam. The images were taken at an average magnification of around 10 and the size of the sensor was around 6.5 m. The data was binned to a size of 1.2 970 m. Key structures of the hearing apparatus were manually segmented. To this end, planes were hand-labelled using 3D Slicer76 (v5.6, https://slicer.org) and then interpolated using Biomedisa (v23)77. The imagej was able to convert between many different file types. The segments were transformed into mesh grids for cleaning and rendering.

Directional bias across trials and fish. The startle trials were pooled across all fish and the fraction of them in one direction was calculated. Using the two-sided binomial test, we calculated how likely a measured directional bias (approach or escape) would have been observed if the response was unbiased.

Pose tracking of D. cerebrum was done with a device called SLEAP75. A skeleton consisting of seven equidistant locations along a fish’s body segments and two additional locations for each eye, was hand-labelled with 140 frames across nine recordings of male and female fish. The ‘single-animal’ model was used for training. The model parameters and the trained model are available at the G-Node repository (see Data availability).

The experimental setup comprised an inner 10 cm × 10 cm (length × width) tank with <200 µm thin optically opaque but acoustically transparent polypropylene sheet walls (cut out of plastic folders), surrounded by an outer tank with submerged speakers (4 × 3 Ekulit LSF-27M/SC 8 Ω in custom waterproof enclosures). Thus, the speakers were visually shielded from the fish inside the inner tank, and the fish were confined between the speakers (Fig. 1c provides a schematic; further details are provided in Extended Data Fig. A,b. The water column was 3.7 cm and the transparent bottom was at 6.3 cm, meaning that the fish wouldn’t find it hard to swim in. The speakers were level with this water column, and all sounds were targeted for this water column. Infrared light-emitting diodes illuminated the fish from below. The fish was live tracked in the inner tank with an overhead camera and filmed with an overhead camera at 120 frames per second. The setup waslit by white light-emitting diodes. The room and water temperature were kept at the correct temperature.

The LAGeSo, the authority for animal experimentation in Berlin, approved all animal experiments that conformed to the regulations of Berlin state, German federal and European Union. The water parameters for the fish in the aquaria were pH 7.3, 350 S cm1, temperature 27 C. Adults were used between 4 and 11 months of age.

Source: The mechanism for directional hearing in fish

Sound stimulation waveforms for particle acceleration measurement: Application to the acoustic stimulator and the galvanometric scanning mirrors

To compute the particle acceleration ({a}_{r}(r,t)) at a distance (r) to a sound monopole with pressure (p(r,t)) for discrete signals of arbitrary waveform, we applied this equation separately for each Fourier component. The pressure was given with samples.

This in turn set additional constraints on the various scanning parameters. We used ({f}{{\rm{scan}}}=800\,{\rm{Hz}}) and ({f}{{\rm{stim}}}=\mathrm{1,000}\,{\rm{Hz}}) for the data presented in Fig. 3 and Extended Data Fig. 11.

To ensure repeatable measurements, the acoustic stimulation and the galvanometric scanning mirrors were synchronized so that each pixel was recorded at a known sound phase. The sound generation was achieved by triggering the frames.

In the section entitled Sound stimulation waveforms, we describe how we defined the pressure and particle motion target waveforms that were conditioned this way.

wavenumber, wavelength, speed of sound, and with Frequency f.

The radial particle velocity decays with distance and limit dependent on Frequency, in a medium of density.

The temporal derivative of particle velocity is called particle acceleration.

The calculation was done for 25 grid positions. The speaker signals were delivered accurately to the target position. Supplementary Table 2 and 3. To ensure consistency over experiments, the water level was kept at precisely 10 cm, and the pressure and acceleration fields inside the inner tank were measured several times (this includes before the first recording and after the last recording).

In the first method, particle acceleration was measured indirectly through the pressure gradient. Newton’s second law of motion (pressure gradient force)

Whereas hydrophones are manufactured and calibrated for underwater use, the particle acceleration sensor is not made to measure particle acceleration underwater and is meant to be glued onto the vibrating object. The PCB sensor should underestimate particle acceleration because of the acoustic impedance mismatch between metal and water.

We compared x and y acceleration waveforms for both measurement methods and found that the acceleration waveforms acquired through the direct method match the waveforms acquired through the indirect method after multiplication by a factor of about 2.4. The close match in rescaled waveforms confirms the validity of the gradient approximation in the indirect method.

Let ({k}{i,p}) be the pressure impulse response kernel, ({k}{i,{a}{x}}) Both the x acceleration impulse response kernels and the y acceleration impulse response kernels should be for the speaker. Using (M) speakers with signal ({s}{i}), pressure and acceleration can be predicted through convolution ((* )):

P_l, mathopsum is limits_i.

Source: The mechanism for directional hearing in fish

Acoustics Analysis of the Trick Configuration with Selective Pressure Inversion by Multi-Speaker Sound Conditioning: a Two-Step Sound Conditioning

To ensure that the trick configuration differed from the single-speaker configuration only by selective pressure inversion, a two-step sound conditioning was carried out. Speaker signals for the single-speaker configuration were calculated first. Then, these signals were effectively fixed to closely resemble the single-speaker signal and only activations of the two speakers along the orthogonal axis were conditioned.