Ab initio aided design of novel quaternary, quinary and senary high-entropy borocarbides

High-entropy materials have attracted considerable interest due to their unique, improved properties and large configurational entropy. Out of these, high-entropy ceramics (HECs) are of particular interest since the independent solubility of cations and anions results in increased configurational entropy. However, most HEC research considers only a single element occupying the anion sublattice, which limits the maximum attainable configurational entropy. Here, we expand our previous work on high-entropy borocarbides where both boron and carbon occupy the anion sublattice. By applying an ab initio based screening procedure, we identify six elements Li, Ti, V, Zr, Nb and Hf suitable for forming high-entropy borocarbides. With these elements, we propose six novel HEC compositions, and by computing their entropy forming ability, we identify that three are likely to form single-phase during synthesis. Material properties and lattice distortions for all proposed compositions are studied using density functional theory calculations with special quasirandom structures. The directional lattice distortions, a concept we introduce in this work, show that lattice distortions have an elemental and directional preference for certain HEC compositions. We also show that the novel inclusion of Li improves the mechanical properties of the proposed HECs, the details of which are studied using the electron localization function.

What do zebrafish prefer? Directional and color preferences in maze tasks

Studies regarding the animals innate preferences help elucidate and avoid probable sources of bias and serve as a reference to improve and develop new behavioral tasks. In zebrafish research, the results of innate directional and color preferences are often not replicated between research groups or even inside the same laboratory raising huge concerns on the replicability and reproducibility. Thus, this study aimed to investigate the male and female zebrafish innate directional and color preferences in the plus-maze and T-maze behavioral tasks. As revealed by the percentage of time spent in each zone of the maze, our results showed that males and females zebrafish demonstrated no difference in directional preference in the plus-maze task. Surprisingly, male and female zebrafish showed color preference differences in the plus-maze task; males did not show any color preference, while female zebrafish demonstrated a red preference compared to white, blue, and yellow colors. Moreover, both male and female zebrafish demonstrated a strong black color preference compared to the white color in the T-maze task. Thus, our results demonstrate the importance of innate preference assays involved with the directionality of the apparatus or the application of colors as a screening process conducting behavioral tests (e.g., anxiety, learning and memory assessment, locomotion, and preference) and highlight the need to analyze sex differences.

The Theoretical Framework of the Clinical Pilates Exercise Method in Managing Non-Specific Chronic Low Back Pain: A Narrative Review

Exercise plays an important role in rehabilitating people with chronic low back pain. Aerobic exercise and resistance training are general exercise strategies to manage chronic low back pain, but these strategies require longer intervention period to achieve clinical outcomes in pain reduction and functional improvements. Directional preference is recognised as an important exercise strategy in managing low back pain. The Clinical Pilates exercise method leverages on the directional preference of an individual to achieve clinical outcomes faster. Clinical Pilates is a hybrid of two of the best exercise interventions for low back pain, which are general Pilates and the McKenzie method. Due to the scarcity of Clinical Pilates literature, a review of its theory and studies was undertaken to provide a structured guide to the technique in managing people with chronic low back pain. Hypothetical algorithms are developed to support translation into clinical practice and future research studies. These algorithms are useful in the management of complex cases involving multiple directional trauma. Although limited, current evidence suggests that the Clinical Pilates exercise method is safe and provides faster functional recovery in the early stage of rehabilitation and similar longer term outcomes as general exercises.

Testing Mate Choice Hypotheses in a Transitional Small Scale Population

Objective Tests of theories of mate choice often rely on data gathered in White, industrialised samples and this is especially the case for studies of facial attraction. Our understanding of preferences for sexual dimorphism is currently in flux and a number of hypotheses require testing in more diverse participant samples. The current study uses opportunistically gathered facial dimorphism preference data from 271 participants in rural Nicaragua, and 40 from the national capital Managua. We assess pre-registered hypotheses drawn from sexual selection theory, and from more recent approaches which consider the impacts of economic development and cultural ‘modernisation’ on mate preferences. Methods Participants verbally reported demographic data, and indicated preferences for five male and five female pairs of faces manipulated to differ in sexually dimorphic facial structure based on a sample of Salvadoran individuals. Results While urban participants showed a preference for more feminine female faces, this preference was not evident in the rural participants. Neither urban nor rural participants showed any directional preference for masculinised/feminised male faces. Furthermore, there was no support for any other pre-registered hypothesis. Conclusions Our results are consistent with previous studies showing no interest in facial dimorphism in less globally-acculturated, or market integrated, populations. Together, this suggests that while facial dimorphism may be subject to systematically varying preferences amongst some low-fertility, industrialised populations, it is not a feature which is likely to have been important in ancestral populations. We call for further work attempting to replicate well known mate choice phenomena in more diverse samples.

Neural Interruption by Unilateral Labyrinthectomy Biases the Directional Preference of Otolith-Related Vestibular Neurons

Background: The directional preference of otolith-related vestibular neurons elucidates the neuroanatomical link of labyrinths, but few direct experimental data have been provided. Methods: The directional preference of otolith-related vestibular neurons was measured in the vestibular nucleus using chemically induced unilateral labyrinthectomy (UL). For the model evaluation, static and dynamic behavioral tests as well as a histological test were performed. Extracellular neural activity was recorded for the neuronal responses to the horizontal head rotation and the linear head translation. Results: Seventy-seven neuronal activities were recorded, and the total population was divided into three groups: left UL (20), sham (35), and right UL (22). Based on directional preference, two sub-groups were again classified as contra- and ipsi-preferred neurons. There was no significance in the number of those sub-groups (contra-, 15/35, 43%; ipsi-, 20/35, 57%) in the sham (p = 0.155). However, more ipsi-preferred neurons (19/22, 86%) were observed after right UL (p = 6.056 × 10−5), while left UL caused more contra-preferred neurons (13/20, 65%) (p = 0.058). In particular, the convergent neurons mainly led this biased difference (ipsi-, 100% after right UL and contra-, 89% after left UL) (p < 0.002). Conclusions: The directional preference of the neurons depended on the side of the lesion, and its dominance was mainly led by the convergent neurons.

Male Mate Choice in Mosquitofish: Personality Outweighs Body Size

Background Despite its important implications in behavioural and evolutionary ecology, male mate choice has been little studied, and the relative contribution of personality and morphological traits remains largely unknown. Using standard two-choice mating trials, we studied whether personality traits (i.e. shyness and activity) and body size of both sexes affect mate choice in male mosquitofish Gambusia affinis. Results Both shyness and activity in males were significantly repeatable and constituted a behavioural syndrome. No overall directional preference for large (or small) females with the same activity levels was detected because larger males preferred larger females and smaller males chose smaller females. However, males spent more time associating with active females regardless of their body lengths and had an enhanced preference for inactive females when they increased activity levels. We also found that more proactive (bolder and more active) males had stronger preferences for more active females. Conclusions Our study supports the importance of body size in male mate choice but highlights that personality traits may outweigh body size preferences when males choose mating partners.

Predicting behavior from eye movement and whisking asymmetry

Navigation through complex environments requires motor planning, motor preparation and the coordination between multiple sensory–motor modalities. For example, the stepping motion when we walk is coordinated with motion of the torso, arms, head and eyes. In rodents, movement of the animal through the environment is often coordinated with whisking. Here we trained head fixed mice – navigating a floating Airtrack plus maze – to overcome their directional preference and use cues indicating the direction of movement expected in each trial. Once cued, mice had to move backward out of a lane, then turn in the correct direction, and enter a new lane. In this simple paradigm, as mice begin to move backward, they position their whiskers asymmetrically: whiskers on one side of the face protract, and on the other side they retract. This asymmetry reflected the turn direction. Additionally, on each trial, mice move their eyes conjugately in the direction of the upcoming turn. Not only do they move their eyes, but saccadic eye movement is coordinated with the asymmetric positioning of the whiskers. Our analysis shows that the asymmetric positioning of the whiskers predicts the direction of turn that mice will make at an earlier stage than eye movement does. We conclude that, when mice move or plan to move in complex real-world environments, their motor plan and behavioral state can be read out in the movement of both their whiskers and eyes.Significance statementNatural behavior occurs in multiple sensory and motor dimensions. When we move through our environment we coordinate the movement of our body, head, eyes and limbs. Here we show that when mice navigate a maze, they move their whiskers and eyes; they position their whiskers asymmetrically, and use saccadic eye movements. The position of the eyes and whiskers predicts the direction mice will turn in. This work suggests that when mice move through their environment, they coordinate the visual-motor and somatosensory-motor systems.

Thermoelastic characterization of carbon nanotube reinforced PDMS elastomer

Internal energy and entropy contribution to the elasticity of carbon nanotube reinforced polydimethylsiloxane (PDMS) is evaluated using statistical theory of rubber elasticity. Stress–temperature measurements were performed and the data was used to calculate the internal energy contribution to elastic stress. Interesting aspects such as increase in energy and low entropy contribution to the elasticity of carbon nanotube reinforced PDMS is observed. This can be related t o the deformation behavior of the network chains of pristine elastomers and the directional reorientation of nanotube entanglements. While the entropy change is associated with reorientation or directional preference of the carbon nanotube entanglements, the internal energy change is associated with structural bending or stretching of the nanotubes. A reversible deformation of nanotube entanglements complements rubber like elasticity and the present study gives insights into the thermoelasticity of reinforced elastomers as well as the elastic behavior of carbon nanotube entanglements inside a polymer matrix.

Quasi-Equivalence of Width and Depth of Neural Networks

While classic studies proved that wide networks allow universal approximation, recent research and successes of deep learning demonstrate the power of the network depth. Based on a symmetric consideration, we investigate if the design of artificial neural networks should have a directional preference, and what the mechanism of interaction is between the width and depth of a network. We address this fundamental question by establishing a quasi-equivalence between the width and depth of ReLU networks. Specifically, we formulate a transformation from an arbitrary ReLU network to a wide network and a deep network for either regression or classification so that an essentially same capability of the original network can be implemented. That is, a deep regression/classification ReLU network has a wide equivalent, and vice versa, subject to an arbitrarily small error. Interestingly, the quasi-equivalence between wide and deep classification ReLU networks is a data-driven version of the DeMorgan law.