Transcranial direct current stimulation combined with swimming exercise improves the learning and memory abilities of vascular dementia rats by regulating microglia through miR-223-3p/PRMT8.

BACKGROUND: Vascular dementia (VD) is the second most common type of dementia worldwide. Previous studies have proven that transcranial direct current stimulation (tDCS) has potential applications in relieving cognitive impairment in VD animal models. The purpose of this study was to probe the mechanism by which tDCS combined with swimming exercise improves the learning and memory abilities of VD model rats. METHOD: The VD rat model was induced using the permanent bilateral common carotid artery occlusion (2-VO) method; tDCS was applied to the rats and then they took part in swimming exercises. Rat memory, platform crossing time, and platform crossing frequency were analyzed via a water maze experiment. Nerve damage in the cortex and hippocampal CA1 area of the rats was observed using Nissl staining. Western blotting, immunohistochemistry, immunofluorescence staining and reverse transcription quantitative polymerase chain reaction (RT - qPCR) were used to determine the expression of related proteins and genes. The levels of oxidative stress were detected by kits. RESULTS: We demonstrated that VD model rats treated with tDCS combined with swimming exercise exhibited significant improvement in memory, and VD model rats exhibited significantly reduced neuronal loss in the hippocampus, and reduced microglial activation and M1 polarization. tDCS combined with swimming exercise protects VD model rats from oxidative stress through the miR-223-3p/protein arginine methyltransferase 8 (PRMT8) axis and inhibits the activation of the TLR4/NF-κB signaling pathway. CONCLUSION: Our results suggest that tDCS combined with swimming exercise improved the learning and memory ability of VD model rats by regulating the expression of PRMT8 through miR-223-3p to affect microglial activation and M1 polarization.

Electricity-Driven Strategies for Bioinspired Multifunctional Swimming Marangoni Robots Based on Super-Aligned Carbon Nanotube Composites.

Marangoni actuators that are propelled by surface tension gradients hold significant potential in small-scale swimming robots. Nevertheless, the release of "fuel" for conventional chemical Marangoni actuators is not easily controllable, and the single swimming function also limits application areas. Constructing controllable Marangoni robots with multifunctions is still a huge challenge. Herein, inspired by water striders, electricity-driven strategies are proposed for a multifunctional swimming Marangoni robot (MSMR), which is fabricated by super-aligned carbon nanotube (SACNT) and polyimide (PI) composite. The MSMR consists of a Marangoni actuator and air-ambient actuators. Owing to the temperature gradient generated by the electrical stimulation on the water surface, the Marangoni actuators can swim controllably with linear, turning, and rotary motions, mimicking the walking motion of water striders. In addition, the Marangoni actuators can also be driven by light. Importantly, the air-ambient actuators fabricated by SACNT/PI bilayer structures demonstrate the function of grasping objects on the water surface when electrically Joule-heated, mimicking the predation behavior of water striders. With the synergistic effect of the Marangoni actuator and air-ambient actuators, the MSMR can navigate mazes with tunnels and grasp objects. This research will provide a new inspiration for smart actuators and swimming robots.

British elite swimmers' experiences and perspectives on life skill development.

This study explores the experiences of British elite swimmers in developing life skills during and throughout their athletic careers, examining the factors that influence their perspectives on this skill development. Six high-profile British swimmers, who have competed at the Commonwealth and/or Olympic Games, were recruited for this study. Semi-structured interviews were conducted, and thematic analysis was applied. Through the analysis, two key themes were identified from the thematic analysis: (a) Implicit life skill development through athletic and educational experience, and (b) Understanding the influence of swimming on life skill development. The first theme includes three sub-themes: (a) Establishment of athletic identity, (b) Prioritization of athletic identity, and (c) Navigating life skills through athletic challenges. The findings show that the swimming careers of participants and their associated identities contributed to the development of a wide range of implicit life skills. This growth was facilitated by both educational and sporting experiences, with all participants reporting positive personal development from their time in competitive swimming. The findings in this study enhance our understanding of life skill development and provide insights into how to more effectively support high-performance athletes in both their athletic careers and educational endeavors.

The Effect of Cold-Water Swimming on Energy Metabolism, Dynamics, and Mitochondrial Biogenesis in the Muscles of Aging Rats.

Our study aimed to explore the potential positive effects of cold water exercise on mitochondrial biogenesis and muscle energy metabolism in aging rats. The study involved 32 male and 32 female rats aged 15 months, randomly assigned to control sedentary animals, animals training in cold water at 5 ± 2 °C, or animals training in water at thermal comfort temperature (36 ± 2 °C). The rats underwent swimming training for nine weeks, gradually increasing the duration of the sessions from 2 min to 4 min per day, five days a week. The results demonstrated that swimming in thermally comfortable water improved the energy metabolism of aging rat muscles (increased metabolic rates expressed as increased ATP, ADP concentration, TAN (total adenine nucleotide) and AEC (adenylate energy charge value)) and increased mRNA and protein expression of fusion regulatory proteins. Similarly, cold-water swimming improved muscle energy metabolism in aging rats, as shown by an increase in muscle energy metabolites and enhanced mitochondrial biogenesis and dynamics. It can be concluded that the additive effect of daily activity in cold water influenced both an increase in the rate of energy metabolism in the muscles of the studied animals and an intensification of mitochondrial biogenesis and dynamics (related to fusion and fragmentation processes). Daily activity in warm water also resulted in an increase in the rate of energy metabolism in muscles, but at the same time did not cause significant changes in mitochondrial dynamics.

Differential Roles of Diet on Development and Spinal Cord Regeneration in Larval Zebrafish.

The zebrafish is a powerful model organism for studying development and regeneration. However, there is a lack of a standardized reference diet for developmental and regeneration experiments. Most studies evaluate the rate of growth, survival, and fecundity. In this study, we compare three diets and their effects on growth and regeneration after a spinal cord injury (SCI). Fish were fed daily for 1 week with daily measurements of overall length and width of spinal injury. Fish fed a live rotifer diet grew 32%, whereas a commercially available diet only led to a 4% increase in body length. Similarly, differences in rate of regeneration were observed with over 80% of rotifer-fed larvae forming a glial bridge after injury compared to <10% of zebrafish fed with the commercial diet. Our data highlight the need for establishing a standardized diet for regeneration studies to improve research reproducibility.

Would Combination Be Better: Swimming Exercise and Intermittent Fasting Improve High-Fat Diet-Induced Nonalcoholic Fatty Liver Disease in Obese Rats via the miR-122-5p/SREBP-1c/CPT1A Pathway.

Background: Swimming and intermittent fasting can both improve obesity-induced NAFLD, but which of the two is more effective and whether the combination of the two has a superimposed effect is inconclusive. Methods: The model of NAFLD in obese rats was established by a high-fat diet and performed swimming, intermittent fasting, and a combination of both interventions for 8 weeks. Serum lipids and enzyme activity were measured by an automatic biochemical analyzer. Liver morphostructural analysis was observed by transmission electron microscopy, and morphology was observed by HE staining. RT‒PCR was used to detect the mRNA level. Results: Morphology and microstructure of the liver of model rats were impaired, with the upregulation of miR-122-5p, SREBP-1c, FASN and ACC1. Eight weeks of swimming exercise, intermittent fasting and the combination of both attenuate these effects, manifested by the downregulation of miR-122-5p and upregulation of CPT1A mRNA levels. There was no significant stacking effect of the combination of the swimming and intermittent fasting interventions. Conclusion: NAFLD leads to pathology in model rats. Eight weeks of swimming exercise, intermittent fasting and the combination of both can inhibit miR-122-5p and improve hepatic lipid metabolism, while no significant additive effects of combining the interventions were found.

Fabrication and characterization of gold nanoparticles using alginate: In vitro and in vivo assessment of its administration effects with swimming exercise on diabetic rats.

Gold nanoparticles (AuNPs) have unique features that might lead to the development of a new class of diabetic medicines. AuNPs were biosynthesized utilizing sodium-alginate. UV-Vis-spectroscopy, Fourier transforms infrared, field emission scanning electron microscopy (FESEM), and energy dispersive X-ray were used to examine the particles. The potential of AuNPs for improving the diabetes condition was examined along with swimming in rats. FESEM image revealed the spherical morphology with an average particle size of 106.6 ± 20.8 nm. In the diabetic group, serum glucose, blood urea nitrogen (BUN), creatinine, cholesterol, and triglyceride (TG) levels were significantly higher than the control group. Low-density lipoprotein (LDL) was significantly higher and high-density lipoprotein (HDL) was significantly lower in the diabetic group compared to the control group. Malondialdehyde (MDA) levels were also significantly higher in the D group. However, in the groups treated with swimming and gold, these parameters were significantly improved. Specifically, serum-glucose, BUN, creatinine, cholesterol, and TG levels were significantly reduced, while LDL was significantly decreased in the diabetic + swimming + AuNPs group and HDL was significantly increased in the diabetic + AuNPs group. MDA levels were significantly decreased in the treated groups, and other antioxidants were significantly improved in the diabetic + swimming + AuNPs group. Catalase levels were also significantly improved in the D + gold group. It can be concluded that both AuNPs and swimming can decrease diabetic complications.

Polysaccharides from Polygonatum kingianum Collett & Hemsl ameliorated fatigue by regulating NRF2/HO-1/NQO1 and AMPK/PGC-1α/TFAM signaling pathways, and gut microbiota.

Polygonatum kingianum Coll & Hemsl is an important Chinese medicine used for enhancing physical function and anti-fatigue, and polysaccharides (PKPs) are considered as the main bioactive components. However, the mechanisms through which PKPs exert their anti-fatigue effects are not fully understood. This study aimed more comprehensively to explore the anti-fatigue mechanisms of PKPs, focusing on metabolism, protein expression, and gut flora, by using exhaustive swimming experiments in mice. Results showed a significant increase in the exhaustive swimming time of the mice treated with PKPs, especially in the high-dose group (200 mg/kg/day). Further studies showed that PKPs remarkably improves several fatigue-related physiological indices. Additionally, 16S rRNA sequence analysis showed that PKPs increased antioxidant bacteria (e.g., g_norank_f_Muribaculaceae) and the production of short-chain fatty acids (SCFAs), while reducing the abundance of harmful bacteria (e.g., g_Escherichia-Shigella and g_Helicobacter). PKPs also mitigated oxidative stress through activating the NRF2/HO-1 signaling pathway, and promoted energy metabolism by upregulating the expression of AMPK/PGC-1α/TFAM signaling pathway proteins. This research may offer theoretical support for incorporating PKPs as a novel dietary supplement in functional foods targeting anti-fatigue properties.

Swimming with a head-mounted display: dual-task costs.

Head-up displays (HUDs) have the potential to change work in operation environments by providing hands-free information to wearers. However, these benefits may be accompanied by trade-offs, primarily by increasing cognitive load due to dividing attention. Previous studies have attempted to understand the trade-offs of HUD usage; however, all of which were focused on land-based tasks. A gap in understanding exists when examining HUD use in aquatic environments as immersion introduces unique environmental and physiological factors that could affect multitasking. In this study, we investigated multitasking performance associated with swimming with a HUD. Eighteen participants completed three tasks: swimming only, a HUD-administered word recall task, and a dual-task combining both tasks. Results revealed significant dual-task interference in both tasks, though possibly less pronounced than in land-based tasks. These findings enhance not only help characterise dual-task performance, but also offer valuable insights for HUD design for aquatic settings.

HUDs have become an increasingly popular tool to present information to users in complex working environments. However, past research examining HUD task performance has been restricted to land-based contexts. The current study examines HUD use while swimming and provides characterisation of multitasking performance within aquatic environments.

Fungus-mediated synthesis of Se-BiO-CuO multimetallic nanoparticles as a potential alternative antimicrobial against ESBL-producing Escherichia coli of veterinary origin.

Bacterial infections emerge as a significant contributor to mortality and morbidity worldwide. Emerging extended-spectrum ß-lactamase (ESBL) Escherichia coli strains provide a greater risk of bacteremia and mortality, are increasingly resistant to antibiotics, and are a major producer of ESBLs. E. coli bacteremia-linked mastitis is one of the most common bacterial diseases in animals, which can affect the quality of the milk and damage organ functions. There is an elevated menace of treatment failure and recurrence of E. coli bacteremia necessitating the adoption of rigorous alternative treatment approaches. In this study, Se-Boil-CuO multimetallic nanoparticles (MMNPs) were synthesized as an alternate treatment from Talaromyces haitouensis extract, and their efficiency in treating ESBL E. coli was confirmed using standard antimicrobial assays. Scanning electron microscopy, UV-visible spectroscopy, and dynamic light scattering were used to validate and characterize the mycosynthesized Se-BiO-CuO MMNPs. UV-visible spectra of Se-BiO-CuO MMNPs showed absorption peak bands at 570, 376, and 290 nm, respectively. The average diameters of the amorphous-shaped Se-BiO-CuO MMNPs synthesized by T. haitouensis extract were approximately 66-80 nm, respectively. Se-BiO-CuO MMNPs (100 µg/mL) showed a maximal inhibition zone of 18.33 ± 0.57 mm against E. coli. Se-BiO-CuO MMNPs also exhibited a deleterious impact on E. coli killing kinetics, biofilm formation, swimming motility, efflux of cellular components, and membrane integrity. The hemolysis assay also confirms the biocompatibility of Se-BiO-CuO MMNPs at the minimum inhibitory concentration (MIC) range. Our findings suggest that Se-BiO-CuO MMNPs may serve as a potential substitute for ESBL E. coli bacteremia.

An Evaluation of the Reliability of the Pictorial Scale of Perceived Water Competence and Its Relationship With Actual Water Competence.

In its recent development, the Pictorial Scale of Perceived Water Competence (PSPWC) showed good face and construct validity. However, additional reliability and validity research is needed, including test-retest reliability and a demonstration of the relationship between PSPWEC test scores and actual water competence. Toward that aim, we administered the PSPWC to 124 children, aged 5-8 years. We repeated this test administration after one week for a subset of 55 children to determine its test-retest reliability, and the remaining 69 children also performed the fully aligned Actual Aquatic Skills Test (AAST) in an indoor swimming pool to provide data for our investigation of the relationship between PSPWC scores and actual water competence. We found good test-retest reliability, both at the global level (ICC = 0.81, n = 55) and at the level of individual skills (Weighted kappa coefficients from 0.58 to 0.90), with no significant differences between these two test scores. We also found a moderate positive relationship between PSPWC and AAST total scores (r = .64, n = 69), with no significant difference between total scores of actual and perceived water competencies. Children overestimated their competence in three specific skills: the back star, swimming on the front, and diving in deep water. While these results underline specific situations in which children's higher self-perceptions of their water competence are a risk factor for their water safety, these data confirm that the PSPWC is reliable for measuring children's perceived competencies in aquatic education and drowning prevention, and there is further support for its validity through a moderate correlation with actual water competencies.

Spontaneous intersibling polymorphism in the development of dopaminergic neuroendocrine cells in sea urchin larvae: impacts on the expansion of marine benthic species.

Introduction: The plasticity of the nervous system plays a crucial role in shaping adaptive neural circuits and corresponding animal behaviors. Understanding the mechanisms underlying neural plasticity during development and its implications for animal adaptation constitutes an intriguing area of research. Sea urchin larvae offer a fascinating subject for investigation due to their remarkable evolutionary and ecological diversity, as well as their diverse developmental forms and behavioral patterns. Materials and methods: We conducted immunochemical and histochemical analyses of serotonin-containing (5-HT-neurons) and dopamine-containing (DA-positive) neurons to study their developmental dynamics in two sea urchin species: Mesocentrotus nudus and Paracentrotus lividus. Our approach involved detailed visualization of 5-HT- and DA-positive neurons at gastrula-pluteus stages, coupled with behavioral assays to assess larval upward and downward swimming in the water column, with a focus on correlating cell numbers with larval swimming ability. Results: The study reveals a heterochronic polymorphism in the appearance of post-oral DA-positive neuroendocrine cells and confirms the stable differentiation pattern of apical 5-HT neurons in larvae of both species. Notably, larvae of the same age exhibit a two- to four-fold difference in DA neurons. An increased number of DA neurons and application of dopamine positively correlate with larval downward swimming, whereas 5-HT-neurons and serotonin application induce upward swimming. The ratio of 5-HT/DA neurons determines the stage-dependent vertical distribution of larvae within the water column. Consequently, larvae from the same generation with a higher number of DA-positive neurons tend to remain at the bottom compared to those with fewer DA-positive neurons. Discussion: The proportion of 5-HT and DA neurons within larvae of the same age underlies the different potentials of individuals for upward and downward swimming. A proposed model illustrates how coordination in humoral regulation, based on heterochrony in DA-positive neuroendocrine cell differentiation, influences larval behavior, mitigates competition between siblings, and ensures optimal population expansion. The study explores the evolutionary and ecological implications of these neuroendocrine adaptations in marine species.

Exploring the Effects of Graphene-Based Nanoparticles on Early Salmonids Cardiorespiratory Responses, Swimming and Nesting Behavior.

Graphene-based nanomaterials are exceptionally attractive for a wide range of applications, raising the likelihood of the release of graphene-containing nanoparticles into aquatic environments. The growing use of these carbon nanomaterials in different industries highlights the crucial need to investigate their environmental impact and evaluate potential risks to living organisms. The current investigation evaluated the nanotoxicity of graphene (nanoflakes) and graphene oxide (GO) nanoparticles on the cardiorespiratory responses (heart rate, gill ventilation frequency), as well as the swimming and nesting behavioral parameters of early stage larvae and juvenile salmonids. Both short-term (96 h) and long-term (23 days) exposure experiments were conducted using two common species: brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss). The findings demonstrated notable alterations in fish nesting behavior, swimming performance, and cardiorespiratory functions, indicating the potential toxicity of nanoparticles. This impact was observed at both physiological and whole-organismal levels in salmonids at early stages. Future investigations should explore different types of nanocarbons and their potential enduring effects on fish population structure, considering not only individual survival but also broader aspects of development, including feeding, reproductive, and other social dynamics.

Swimming ability of Schizothoracinae fishes in Yarlung Zangbo River of China.

The Yarlung Zangbo River is a river with abundant hydropower resources but fragile biodiversity in China. As an important benchmark for both research and ecological management, there is still a lack of knowledge about the swimming ability of fishes in the Yarlung Zangbo River. The induced flow velocity (Uind), critical swimming speed (Ucrit), and burst swimming speed (Uburst) of five Schizothoracinae species were tested in this study. Relative swimming ability related to body length and body shape was calculated. The results indicated that the average absolute swimming speeds (Uind-a, Ucrit-a, and Uburst-a) of all the experimental fish were 10.20 ± 0.01, 57.58 ± 3.28, and 69.54 ± 2.94 cm/s, respectively, and the corresponding relative Uind, Ucrit, and Uburst related to body length (Uind-l, Ucrit-l, Uburst-l) were 1.15 ± 0.07, 5.04 ± 0.26, and 7.23 ± 0.28 BL/s, respectively. Moreover, relative Uind, Ucrit, and Uburst related to body shape (Uind-s, Ucrit-s, and Uburst-s) were 0.80 ± 0.13, 2.49 ± 0.51, and 4.32 ± 0.57 cm-2/s, respectively. No significantly differences in relative swimming speeds existed among five species. Only Oxygymnocypris stewartii was significantly weaker in Uburst-s than Schizothorax o'connori. The body shape showed a stronger relationship with swimming speed than the body length did. Schizothoracinae fish in the Yarlung Zangbo River basin are less sensitive to the water flow and performed weaker Ucrit and Uburst compared to those in the Yangtze River basin, indicating that Schizothoracinae fish in the Yarlung Zangbo River may be more susceptible to threats from environmental changes. The paper enriched the research on the swimming ability of Schizothoracinae fishes and provided efficient data for the fish conservation in the Yarlung Zangbo River.

Unique behavioral patterns of wandering colonies of Brevibacillus thermoruber on agar plates.

Brevibacillus thermoruber strain Nabari cells grow as widely spreading dendritic colonies on reasoner's 2A-agar (1.5%) plates at around 55°C but as small motile colonies at 37°C. Motile colonies can be divided into colonies that move in straight or curved lines over long distances (wandering colonies), and colonies that rotate at a fixed location (rotating colonies). The addition of surfactant to the agar medium greatly increased the frequency of wandering colonies and facilitated the study of such colonies. The morphology of the wandering colonies varied: circular at the tip and pointed at the back, lemon-shaped with pointed ends, crescent-shaped, bullet-shaped, fish-like, and so on. A single colony may split into multiple colonies as it moves, or multiple colonies may merge into a single colony. The most surprising aspect of the movement of wandering colonies was that when a moving colony collides with another colony, it sometimes does not make a U-turn, but instead retreats straight back, as if bouncing back. The migration mechanisms of wandering colonies are discussed based on optical microscopic observations of swimming patterns of single cells in water and scanning electron microscopy of the arrangement of bacterial cells in wandering colonies.

Peak Performance: Characteristics and Key Factors in the Development of the World Top-8 Swimmers Based on Longitudinal Data.

PURPOSE: This study aimed to investigate the peak performance characteristics of the world top-8 swimmers and the key factors involved in the journey toward achieving better peak performance. METHODS: The results of the world top-8 swimmers from 2001 to 2022 were collected from the World Aquatics performance database. Progression to peak performance was tracked with individual quadratic trajectories (1191 cases). Utilizing k-means clustering to group competitive feature variables, this study investigated key developmental factors through a binary logistic regression model, using the odds ratio (OR) to represent whether a factor was favorable (OR > 1) or unfavorable (OR < 1). RESULTS: Significant differences (P < .001) in the peak age between men (23.54/3.80) and women (22.31/4.60) were noticed, while no significant differences (P > .05) in the peak-performance window for both sexes appeared. Peak performance occurred at later ages for the sprint for both sexes, and women had a longer duration in peak-performance window for sprint (P < .05). Peak-performance occurred at later ages for the breaststroke and butterfly for both sexes (P < .05). Binary logistic regression revealed that high first-participation performance (OR = 1.502), high major-competition performance (OR = 4.165), early first-major-competition age (OR = 1.441), participation frequency above 4 times/year in both phase 2 (4.3-8.0 times/y, OR = 3.940; 8.1-20.0 times/y, OR = 5.122) and phase 3 (4.1-7.5 times/y: OR = 5.548; 7.7-15.0 times/y: OR = 7.526), and a career length of 10 years or more (10-15 y, OR = 2.102; 16-31 y, OR = 3.480) were favorable factors for achieving better peak performance. CONCLUSIONS: Peak performance characteristics varied across sex, swimming stroke, and race distance in the world top-8 swimmers. Meanwhile, the research indicated that certain specific developmental factors were key conditions for the world top-8 swimmers to achieve better peak performance in the future.

Larval swimming in the sea anemone Nematostella vectensis is sensitive to a broad light spectrum and exhibits a wavelength-dependent behavioral switch.

In nearly all animals, light-sensing mediated by opsin visual pigments is important for survival and reproduction. Eyeless light-sensing systems, though vital for many animals, have received relatively less attention than forms with charismatic or complex eyes. Despite no single light-sensing organ, the sea anemone Nematostella vectensis has 29 opsin genes and multiple light-mediated behaviors throughout development and reproduction, suggesting a deceptively complex light-sensing system. To characterize one aspect of this light-sensing system, we analyzed larval swimming behavior at high wavelength resolution across the ultraviolet and visual spectrum. N. vectensis larvae respond to light at least from 315 to 650 nm, which is a broad sensitivity range even compared to many animals with complex eyes. Planktonic swimming is induced by ultraviolet (UV) and violet wavelengths until 420 nm. Between 420 and 430 nm a behavioral switch occurs where at wavelengths longer than 430 nm, larvae respond to light by swimming down. Swimming down toward the substrate is distinct from light avoidance, as animals do not exhibit positive or negative phototaxis at any wavelength tested. At wavelengths longer than 575 nm, animals in the water column take increasingly longer to respond and this behavior is more variable until 650 nm where larval response is no different from the dark, suggesting these longer wavelengths lie outside of their sensitivity range. Larval swimming is the only motile stage in the life history of N. vectensis, and increased planktonic swimming could lead to greater dispersal range in potentially damaging shallow environments with short-wavelength light exposure. Longer wavelength environments may indicate more suitable substrates for metamorphosis into the polyp stage, where the individual will remain for the rest of its life. Future work will test whether this robust behavior is mediated by multiple opsins.

Exploring altered bovine sperm trajectories by sperm tracking in unconfined conditions.

Mammalian sperm motility is getting more relevant due to rising infertility rates worldwide, generating the need to improve conventional analysis and diagnostic approaches. Nowadays, computer assisted sperm analysis (CASA) technologies represent a popular alternative to manual examination which is generally performed by observing sperm motility in very confined geometries. However, under physiological conditions, sperm describe three-dimensional motility patterns which are not well reconstructed by the limited depth of standard acquisition chambers. Therefore, affordable and more versatile alternatives are needed. Here, a motility analysis in unconfined conditions is proposed. In details, the analysis is characterized by a significant longer duration -with respect to conventional systems- with the aim to observe eventually altered motility patterns. Brightfield acquisition in rectangular glass capillaries captured frozen-thawed bovine spermatozoa which were analyzed by means of a self-written tracking routine and classified in sub-populations, based on their curvilinear velocity. To test the versatility of our approach, cypermethrin -a commonly used pesticides- known to be responsible for changes in sperm motility was employed, assessing its effect at three different time-steps. Experimental results showed that such drug induces an increase in sperm velocity and progressiveness as well as circular pattern formation, likely independent of wall interactions. Moreover, this resulted in a redistribution of sperm with the rapid class declining in number with time, but still showing an overall velocity increase. The flexibility of the approach permits parameter modifications with the experimental needs, allowing us to conduct a comprehensive examination of sperm motility. This adaptability facilitated data acquisition which can be computed at different frame rates, extended time periods, and within deeper observation chambers. The suggested approach for sperm analysis exhibits potential as a valuable augmentation to current diagnostic instruments.

The axial skeleton of Tiktaalik roseae.

The axial columns of the earliest limbed vertebrates show distinct patterns of regionalization as compared to early tetrapodomorphs. Included among their novel features are sacral ribs, which provide linkage between the vertebral column and pelvis, contributing to body support and propulsion by the hindlimb. Data on the axial skeletons of the closest relatives of limbed vertebrates are sparce, with key features of specimens potentially covered by matrix. Therefore, it is unclear in what sequence and under what functional context specializations in the axial skeletons of tetrapods arose. Here, we describe the axial skeleton of the elpistostegalian Tiktaalik roseae and show that transformations to the axial column for head mobility, body support, and pelvic fin buttressing evolved in finned vertebrates prior to the origin of limbs. No atlas-axis complex is observed; however, an independent basioccipital-exoccipital complex suggests increased mobility at the occipital vertebral junction. While the construction of vertebrae in Tiktaalik is similar to early tetrapodomorphs, its ribs possess a specialized sacral domain. Sacral ribs are expanded and ventrally curved, indicating likely attachment to the expanded iliac blade of the pelvis by ligamentous connection. Thus, the origin of novel rib types preceded major alterations to trunk vertebrae, and linkage between pelvic fins and axial column preceded the origin of limbs. These data reveal an unexpected combination of post-cranial skeletal characters, informing hypotheses of body posture and movement in the closest relatives of limbed vertebrates.