Arquimea (Spain)

Functional Near-Infrared Spectroscopy (fNIRS) is a significant technology for assessing changes in tissue hemoglobin concentrations [1]. It offers a cost-effective, portable alternative to fMRI for monitoring brain activity and hemodynamics [1], [2]. Current fNIRS techniques include continuous wave (CW), frequency-domain (FD) and time-domain (TD), each with limitations in penetration depth or complexity [3], [4]. This study introduces a novel dual-comb fNIRS (DC-fNIRS) technique, which uses two optical frequency combs generated from a single laser source [5]. This approach allows for the measurement of the tissue's frequency response, including the diffuse time of flight (DTOF), by sampling its amplitude and phase [4], [5]. The method has been demonstrated to retrieve the impulse response of the medium in transmission, enabling the measurement of absolute optical properties [5].

Saving power is one of the most important things in space applications and power consumption has a direct impact on system complexity and costs. One straightforward approach to reduce the power of digital systems is to stop the clock activity, i.e., clock gating (CG). When circuits are exposed to radiation and the clock activity has stopped, resulting upsets accumulate and may destroy the systems’ configuration. Thus, a self-correction (SC) mechanism has to be developed in order to mitigate Single Event Effects (SEE) even though the clock signals are deactivated. This paper proposes a circuit solution for self-correcting Radiation-Hardening-by-Design (RHBD) Triple Modular Redundancy (TMR) flip-flops. The transistor - and gate-level schemes are presented, discussed and compared. A prototype chip is fabricated in a 130 nm BiCMOS technology. Radiation results show a robustness in LET above $52.5 \mathrm{MeV} \mathrm{cm}^{2} \mathrm{mg}^{-1}$ for the novel self-correcting RHBD TMR flip-flop.

The present study compares two protocols for the cryopreservation of chicken semen. Both protocols had an initial low cooling rate in the first step, followed by higher cooling rates around ice nucleation (Protocol 1) or following the dissipation of the latent heat of fusion (Protocol 2) in the second step. Semen ejaculates obtained from 12 roosters were diluted with Rootex with 6% dimethylformamide and frozen following either Protocol 1 (from +5°C to -10°C at 5°C/min and from -10°C to -130°C at 60°C/min) or Protocol 2 (from +5°C to -35°C at 7°C/min and from -35°C to -140°C at 60°C/min). Compared with fresh semen, following both protocols, cryopreservation resulted in reduced post-thaw sperm quality (p < .001). Post-thaw percentage of sperm with an intact plasma membrane was greater using Protocol 2 than Protocol 1 (p < .05). The results suggest that high cooling rates around the time of ice nucleation are not recommendable.

While original Neural Radiance Fields (NeRF) have shown impressive results in modeling the appearance of a scene with compact MLP architectures, they are not able to achieve real-time rendering. This has been recently addressed by either baking the outputs of NeRF into a data structure or arranging trainable parameters in an explicit feature grid. These strategies, however, significantly increase the memory footprint of the model which prevents their deployment on bandwidth-constrained applications. In this paper, we extend the grid-based approach to achieve real-time view synthesis at more than 150 FPS using a lightweight model. Our main contribution is a novel architecture in which the density field of NeRF-based representations is split into N regions and the density is modeled using N different decoders which reuse the same feature grid. This results in a smaller grid where each feature is located in more than one spatial position, forcing them to learn a compact representation that is valid for different parts of the scene. We further reduce the size of the final model by disposing of the features symmetrically on each region, which favors feature pruning after training while also allowing smooth gradient transitions between neighboring voxels. An exhaustive evaluation demonstrates that our method achieves real-time performance and quality metrics on a pair with state-of-the-art with an improvement of more than 2× in the FPS/MB ratio.

Controlling soft robots is a significant challenge due to the nonlinear elastic nature of the soft materials that conform their structure. This paper studies the identification and control problems of a novel two-degrees-of-freedom, tendon-actuated, soft robotic arm. A decoupled identification approach is presented; later, a fractional order control strategy is proposed and tested experimentally, in comparison with PI solutions. The simulation and experimental results show the goodness of the modeling and control approaches discussed.

We present a new functional near-infrared technique (HET-fNIRS) based on heterodyne optical detection applied to dispersive media that offers high phase resolution (10mrad) and fast temporal resolution (5ms) with noiseless optical gain (enhanced depth range).

The domestication process has resulted in profound changes in the reproductive physiology of the animals that might have affected the sperm characteristics and thus their sensitivity to handling and cryopreservation procedures. This work assesses the response of the sperm of domestic and wild ungulates to a cooling storage at 15°C for 20 h followed by incubation at 38.5°C, 5% CO2, for 2 h. In addition, this paper examines the most representative sperm traits to assess their responsiveness to these stress conditions. Sperm samples were collected from domestic and their wild ancestor species: ram, mouflon, buck, Iberian ibex, domestic boar, and wild boar. Sperm motility, viability, mitochondrial membrane status, DNA fragmentation, and reactive oxygen species production were evaluated at the beginning of the experiment, after 20 h of refrigeration at 15°C, and, finally, at 2 h of incubation at 38.5°C. Sperm from all domestic species (ram, buck, and domestic boar) suffered more stress than their wild relatives (mouflon, Iberian Ibex, and wild boar). In pigs, the percentage of intact mitochondria was lower in the domestic species compared to wild boar. In sheep, we found a higher reactive oxygen species production in rams, while in goats, the curvilinear velocity was lower in the domestic species. The PCA (principal components analysis) showed that the motility and their kinetic variables were the most represented variables in the principal components of all species, indicating that they are essential biomarkers for evaluating the stress response. Sperm viability was highlighted as a representative variable for evaluating the stress response in domestic boar, mouflon, ram, and ibex.

The magnetometer instrument on the Solar Orbiter mission is designed to measure the magnetic field local to the spacecraft continuously for the entire mission duration. The need to characterise not only the background magnetic field but also its variations on scales from far above to well below the proton gyroscale result in challenging requirements on stability, precision, and noise, as well as magnetic and operational limitations on both the spacecraft and other instruments. The challenging vibration and thermal environment has led to significant development of the mechanical sensor design. The overall instrument design, performance, data products, and operational strategy are described.