High water temperature significantly influences swimming performance of New Zealand migratory species.

Anthropogenic structures in freshwater systems pose a significant threat by fragmenting habitats. Effective fish passage solutions must consider how environmental changes introduce variability into swimming performance. As temperature is considered the most important external factor influencing fish physiology, it is especially important to consider its effects on fish swimming performance. Even minor alterations in water properties, such as temperature and velocity, can profoundly affect fish metabolic demands, foraging behaviours, fitness and, consequently, swimming performance and passage success. In this study, we investigated the impact of varying water temperatures on the critical swimming speeds of four migratory New Zealand species. Our findings revealed a significant reduction in critical swimming speeds at higher water temperatures (26°C) compared to lower ones (8 and 15°C) for three out of four species (Galaxias maculatus, Galaxias brevipinnis and Gobiomorphus cotidianus). In contrast, Galaxias fasciatus exhibited no significant temperature-related changes in swimming performance, suggesting species-specific responses to temperature. The cold temperature treatment did not impact swimming performance for any of the studied species. As high water temperatures significantly reduce fish swimming performance, it is important to ensure that fish passage solutions are designed to accommodate a range of temperature changes, including spatial and temporal changes, ranging from diel to decadal fluctuations. Our research underscores the importance of incorporating temperature effects into fish passage models for habitat restoration, connectivity initiatives, and freshwater fish conservation. The influence of temperature on fish swimming performance can alter migration patterns and population dynamics, highlighting the need for adaptive conservation strategies. To ensure the resilience of freshwater ecosystems it is important to account for the impact of temperature on fish swimming performance, particularly in the context of a changing climate.

Flagellar protein FliL: A many-splendored thing.

FliL is a bacterial flagellar protein demonstrated to associate with, and regulate ion flow through, the stator complex in a diverse array of bacterial species. FliL is also implicated in additional functions such as stabilizing the flagellar rod, modulating rotor bias, sensing the surface, and regulating gene expression. How can one protein do so many things? Its location is paramount to understanding its numerous functions. This review will look at the evidence, attempt to resolve some conflicting findings, and offer new thoughts on FliL.

Identifying evidence-practice gaps for shoulder injury risk factors in competitive swimmers: uniting literature and expert opinion.

OBJECTIVES: To identify evidence-practice gaps regarding shoulder injury risk factors in competitive swimmers. METHODS: We gathered insights from 27 swimming experts including elite swimmers, coaches, high-performance staff and applied researchers using Concept Mapping. Participants brainstormed, sorted and rated (from 1 (least) to 10 (most) important and modifiable) their ideas of shoulder injury risk factors in competitive swimmers. Proposed risk factors rated above the grand mean for importance (6.2±0.4) or modifiability (6.5±0.5) ratings were considered highly important/modifiable. Expert opinions were then juxtaposed with systematic review findings to identify overlaps or convergences. RESULTS: Brainstorming generated 126 proposed shoulder injury risk factors for competitive swimmers, subsequently refined to 61 unique proposed risk factors by removing duplicates and combining similar responses. The participants sorted the 61 risk factors into seven distinct clusters. Experts perceived 36/61 proposed risk factors as highly important, of which 6 were supported by literature, 6 showed no association with injury, 2 had conflicting evidence and the remaining 22 have not yet been investigated, suggesting an evidence-practice gap. Three proposed risk factors 'inconsistent training load', 'poor stroke technique' and 'low posterior shoulder strength-endurance' exhibited high perceived importance, high perceived modifiability and supporting evidence. CONCLUSION: An evidence-practice gap was identified for 28 proposed risk factors perceived as highly important by swimming experts despite either (1) no relevant empirical research (n=22), or (2) no association with injury (n=6) from synthesised evidence. Greater collaboration between researchers and practitioners is needed to effectively address shoulder injury risk factors in competitive swimmers.

Critical swimming speed at different temperatures for small-bodied freshwater native riverine fish species.

This study evaluated the effect of fish total length (LT) and three water temperatures (10, 15 and 20 °C) on the critical swimming speed (Ucrit) of the species Percilia irwini (2.9-6.3 cm LT), Cheirodon galusdae (3.4-5.5 cm LT), and Trichomycterus areolatus (4.0-6.3 cm LT). An Ucrit estimation model was constructed for each species as a function of temperature and size. The results showed mean Ucrit for P. irwini of 44.56, 53.83 and 63.2 cm s-1 at 10, 15 and 20 °C, respectively: 55.34, 61.74 and 70.05 cm s-1 for C. galusdae and 56.18, 63.01 and 71.09 cm s-1 for T. areolatus. Critical velocity depended on the interaction between species, body length and water. The swimming performance increased significantly with rising temperature in all three species. The velocity also increased with greater fish total length. After controlling for fish total length, velocity also increased with higher temperature in the three species. This research is relevant to small fish species that require conservation measures.

The methodology of resistance training is crucial for improving short-medium distance front crawl performance in competitive swimmers: a systematic review and meta-analysis.

Background: Resistance training is often a part of the routine training regimen for competitive swimmers. However, due to the variety of resistance training methodology, the results can be inconsistent and sometimes unsatisfactory. Clear recommendations are still lacking at present. Aims: 1) Quantify the impact of resistance training on swimmers' upper limb maximum strength, front crawl performance and key technical parameters; 2) Find out the key technical parameters for improving front crawl performance-stroke rate or length; 3) Through subgroup analysis determine the best methodology of resistance training to enhance the front crawl. Methods: Systematic search in the PubMed, Embase, and Web of Science databases. Meta-analyses using the inverse-variance are performed to compare swimmers' upper limb maximum strength, front crawl performance and key technical parameters in resistance training and habitual aquatic training. A subgroup analysis was performed to examine whether the results were affected by the methodology of resistance training. Results: Thirteen studies (267 competitive swimmers) met the inclusion criteria. The results of meta-analysis showed that resistance training significantly improved upper limbs maximum muscle strength, and 25, 50, 100, and 200 m front crawl performance in competitive swimmers. And improvements in swimming performance may simply resulted from resistance training increasing stroke rate rather than stroke length. In addition, the results of subgroup analysis showed that only concurrent resistance training (CRT) and power training (PT) ultimately improved swimming performance by increasing the maximum muscle strength of the upper limbs. Conclusion: Resistance training significantly enhances competitive swimmers' upper limb strength and front crawl performance across various distances. The improvement in performance is likely attributed to an increased stroke rate rather than stroke length. In addition, CRT and PT are particularly effective, indicating the importance of selecting the appropriate methodology of resistance training for optimal swimming performance enhancement. Systematic review registration: https://doi.org/10.17605/OSF.IO/3JEGW.

Changes in Young Swimmers' In-Water Force, Performance, Kinematics, and Anthropometrics over a Full Competitive Season.

The aim of the present study was to analyze changes in young swimmers' in-water force, performance, kinematics, and anthropometrics during one full competitive season. Twenty-five swimmers (11 girls and 14 boys, 12.04 ± 0.16 years) were assessed over four distinct time points throughout a competitive season. The in-water force of both hands (D, dominant; ND, non-dominant) was retrieved during two bouts of 25 m front crawl allowing the estimation of the symmetry index. The velocity (v25) was calculated from the time to complete the 25 m and considered the performance outcome, while the stroke rate, stroke length, and the stroke index were used as kinematic variables. For anthropometric variables, body mass, stature, arm span and the hand surface area were measured. The in-water force (16-24%) and performance (8%) improved over the competitive season with significant changes in the first macrocycle. The stroke index was the only kinematic variable that changed between M1 and M4 (12.7%), accompanied by a higher asymmetric motion later in the season. A time effect was found in the stature (p < 0.001, ηp 2 = 0.71), the arm span (p < 0.001, ηp 2 = 0.79), and the hand surface area (D = p < 0.001, ηp 2 = 0.63; ND = p < 0.001, ηp 2 = 0.666). Swimming performance showed associations with in-water force, stroke efficiency and anthropometric features in all time points of the season. Thus, the natural anthropometric growth experienced over the season may translate into a more efficient swimming pattern with greater in-water forces that can enhance performance.

Negative prior aquatic experiences and children's aquatic competency: Do parent perceptions differ from reality?

ISSUE ADDRESSED: Achieving aquatic competence is recommended for preventing childhood drownings, yet many children in Victoria, Australia do not meet aquatic benchmarks despite participating in swimming and water safety programs. While few studies have explored factors influencing aquatic competency development, negative prior aquatic experiences (NPAE) have surfaced as a potential influence. Research on children's NPAE has primarily focused on parental perceptions rather than the child's actual experiences. METHODS: Parents and children (aged 10-12 years) completed reliable surveys for background information and NPAE-related data. Children also completed aquatic competency assessments against benchmark standards. Chi-square tests determined relationships between NPAE and aquatic competency, and thematic analysis categorised themes related to perceptions of the child's NPAE. RESULTS: Most parents (82.9%) indicated their child had not had NPAE, while only half (51.0%) of children did not report NPAE. Children reporting NPAE often perceived incidents as nearly drowning (41%), encompassing swimming pool environments and underwater submersion. Similarly, parents reported varied situations, noting NPAE involving open water and the child's loss of control. Parent-reported NPAE was associated with children less likely to achieve knowledge, continuous swimming, and survival competency benchmarks (p < .05). Children reporting NPAE were less likely to achieve underwater competencies (p < .05). CONCLUSIONS: The disparity between parent and child perspectives of NPAE demonstrates the importance of considering both perspectives. This should assist in providing appropriate support for children to develop aquatic competencies. SO WHAT?: Using NPAE data, practitioners can customise swim teaching approaches to address and prevent NPAE, particularly as many children associate their NPAE with pools, the common setting for aquatic education.

Directional swimming patterns in jellyfish aggregations.

Having a profound influence on marine and coastal environments worldwide, jellyfish hold significant scientific, economic, and public interest.1,2,3,4,5 The predictability of outbreaks and dispersion of jellyfish is limited by a fundamental gap in our understanding of their movement. Although there is evidence that jellyfish may actively affect their position,6,7,8,9,10 the role of active swimming in controlling jellyfish movement, and the characteristics of jellyfish swimming behavior, are not well understood. Consequently, jellyfish are often regarded as passively drifting or randomly moving organisms, both conceptually2,11 and in process studies.12,13,14 Here we show that the movement of jellyfish is modulated by distinctly directional swimming patterns that are oriented away from the coast and against the direction of surface gravity waves. Taking a Lagrangian viewpoint from drone videos that allows the tracking of multiple adjacent jellyfish, and focusing on the scyphozoan jellyfish Rhopilema nomadica as a model organism, we show that the behavior of individual jellyfish translates into a synchronized directional swimming of the aggregation as a whole. Numerical simulations show that this counter-wave swimming behavior results in biased correlated random-walk movement patterns that reduce the risk of stranding, thus providing jellyfish with an adaptive advantage critical to their survival. Our results emphasize the importance of active swimming in regulating jellyfish movement and open the way for a more accurate representation in model studies, thus improving the predictability of jellyfish outbreaks and their dispersion and contributing to our ability to mitigate their possible impact on coastal infrastructure and populations.

Fish communicate with water flow to enhance a school's social network.

Schooling fish rely on a social network created through signaling between its members to interact with their environment. Previous studies have established that vision is necessary for schooling and that flow sensing by the lateral-line system may aid in a school's cohesion. However, it remains unclear to what extent flow provides a channel of communication between schooling fish. Based on kinematic measurements of the speed and heading of schooling tetras (Petitella rhodostoma), we found that compromising the lateral line by chemical treatment reduced the mutual information between individuals by ∼13%. This relatively small reduction in pairwise communication propagated through schools of varying size to reduce the degree and connectivity of the social network by more than half. Treated schools additionally showed more than twice the spatial heterogeneity of fish with unaltered flow sensing. These effects were much more substantial than the changes that we measured in the nearest-neighbor distance, speed, and intermittency of individual fish by compromising flow sensing. Therefore, flow serves as a valuable supplement to visual communication in a manner that is revealed through a school's network properties.

Shoulder Pain in Competitive Swimmers: A Multi-Site Survey Study.

Background: There are 2.8 million youth competitive swimmers in the United States (US), and shoulder pain is the most common complaint among swimmers. Purpose: To determine prevalence of shoulder pain, disability, and dissatisfaction in youth competitive swimmers. A secondary purpose was to determine influence of age, competitive swimming experience, and previous history of shoulder pain or injury on shoulder pain, disability, and dissatisfaction, and finally to determine if sex, geographic area, and participation in a second sport relate to shoulder pain, disability, and dissatisfaction. Study Design: Multi-site cross-sectional design. Methods: Six-hundred and seventy-one swimmers aged 9-17 years from six states in the US completed surveys which included demographics, the Penn Shoulder Score (PSS), and the Disability of Arm Shoulder Hand (DASH) Sports. Independent t-tests were used to compare pain, disability, dissatisfaction, the influence of age, sex, participation in second sport, geographic region, and history of shoulder pain. Linear regression analyses were performed to determine the interaction of these variables with reported pain and disability. Results: Forty-nine percent of swimmers had shoulder symptoms. Greater shoulder pain and disability were reported in 15 to 17-year-olds compared to 9 to 10-year-olds (pain and disability: p<0.001), in swimmers with greater versus less years of experience (pain and disability: p<0.001), and in swimmers from eastern versus western states (pain: p=0.001, disability: p=0.0014). Swimmers not participating in a second sport had higher shoulder dissatisfaction (p=0.002). History of prior shoulder pain/traumatic injury was the best indicator of increased pain, disability, and dissatisfaction (p<0.001). Conclusion: Almost half of swimmers surveyed had shoulder pain, with a higher prevalence found in older age groups, those with greater experience, and in those with prior shoulder pain or traumatic injury. Further research should investigate shoulder pain prevention programs, and surveillance methods are recommended to identify symptomatic swimmers who may benefit from referral to prevent further pain and disability. Level of Evidence: III.

On-site extraction of benzophenones from swimming pool water using hybrid tapes based on the integration of hydrophilic-lipophilic balance microparticles and an outer magnetic nanometric domain.

An on-site extraction device is presented consisting of scotch tape modified with concentric domains of micrometric hydrophilic-lipophilic balance (HLB) particles surrounded by a ring of nanometric magnetic ones. On the one hand, HLB microparticles are readily available at the surface of the tape, exposed to interact with the target analytes, being responsible for the extraction capacity of the sorptive phase. On the other hand, the presence of magnetic nanoparticles enables the attachment of the modified tape onto a metallic screw via a magnet, which is then coupled to a wireless drill, enabling the stirring of the microextraction device. Both are simply fixed to the cost-effective, flexible, and versatile support, i.e., scotch tape, owing to their adhesive properties. The microextraction device has been applied to the determination of six benzophenones in swimming pool water samples. The variables that may affect the extraction process have been evaluated. Under the optimum conditions and using liquid chromatography-tandem mass spectrometry as the instrumental technique, the method provided a limit of detection of 0.03 µg L-1. The intra-day precision, evaluated at three different concentration levels and expressed as relative standard deviation, was lower than 10%, which also comprises the variability within single-use sorptive tapes. The accuracy, calculated with spiked samples and expressed as relative recovery, ranged from 71 to 138%. The method was applied to the analysis of swimming pool water, revealing the presence of such compounds.

Agreement between an automated video-based system and tethered system to measure instantaneous swimming velocity.

Successful performance in competitive swimming requires a swimmer to maximise propulsion and minimise drag, which can be assessed using instantaneous swimming velocity. Many systems exist to quantify velocity, and therefore, it is important to understand the agreement between systems. This study examined the agreement between an automated video-based system and a tethered system to measure instantaneous velocity. Twenty-two competitive swimmers (state level or higher) completed 25 m of each stroke at maximal intensity. The tethered speedometer was attached to the swimmer's waist, while videos of each trial were recorded. The swimmer's head was then automatically tracked using proprietary software, and instantaneous velocity was determined from each system. Bland-Altman plots showed good agreement between the two systems in backstroke (95% Limits of Agreement (LOA): -0.24-0.26 m.s-1) and freestyle (95% LOA: -0.36-0.38 m.s-1) but poorer agreement in butterfly (95% LOA: -0.51-0.53 m.s-1) and breaststroke (95% LOA: -0.88-0.92 m.s-1). The root mean square error was higher in butterfly (0.27 m.s-1) and breaststroke (0.46 m.s-1) compared to backstroke (0.13 m.s-1) and freestyle (0.19 m.s-1). Results demonstrated that the two systems are comparable for measuring instantaneous swimming velocity; however, larger discrepancies are evident for butterfly and breaststroke.

The swimming habits of women who cold water swim.

BACKGROUND: Cold water swimming is growing in popularity, especially among women. We have previously reported that women felt that cold water swimming helps with their menstrual and menopause symptoms. But little is known about the habits of women who cold water swim. OBJECTIVES: To determine the habits of women who cold water swim. DESIGN: This was a mixed-methods study. METHODS: An online survey asked women who cold water swim about their experience of swimming and how this affected their menstrual and menopause symptoms. The survey was advertised for 2 months on social media, with a focus on advertising in cold water swimming Facebook groups. In this article, only the questions on the women's swimming habits were analyzed. RESULTS: The analysis of 1114 women, mainly from the United Kingdom, revealed that most had been swimming for 1-5 years (79.5%). Most swim in the sea (64.4%), and only 15.5% swim alone. The majority (89.0%) swim all year around, swimming for mainly 30-60 min in the summer and 5-15 min in the winter. The women mostly swim wearing swimming costumes (skins) throughout the year. The majority of the free-text responses showed women found mental and physical benefits from cold water swimming. CONCLUSION: It was not surprising to learn that women swim for longer in the summer than the winter, but hearing how they feel cold water swimming helps their physical and mental health is important. With the limitations on access and safety of many wild swimming sites in the United Kingdom, it is time to ensure that cold water swimming is safer and more supported.

Sprinting to the top: comparing quality of distance variety and specialization between swimmers and runners.

Objectives: To compare performance progression and variety in race distances of comparable lengths (timewise) between pool swimming and track running. Quality of within-sport variety was determined as the performance differences between individual athletes' main and secondary race distances across (top-) elite and (highly-) trained swimmers and runners. Methods: A total of 3,827,947 race times were used to calculate performance points (race times relative to the world record) for freestyle swimmers (n = 12,588 males and n = 7,561 females) and track runners (n = 9,230 males and n = 5,841 females). Athletes were ranked based on their personal best at peak performance age, then annual best times were retrospectively traced throughout adolescence. Results: Performance of world-class swimmers differentiates at an earlier age from their lower ranked peers (15-16 vs. 17-20 year age categories, P < 0.05), but also plateaus earlier towards senior age compared to runners (19-20 vs. 23 + year age category, P < 0.05), respectively. Performance development of swimmers shows a logarithmic pattern, while runners develop linearly. While swimmers compete in more secondary race distances (larger within-sport variety), runners specialize in either sprint, middle- or long-distance early in their career and compete in only 2, 4 or 3 other race distances, respectively. In both sports, sprinters specialize the most (P < 0.05). Distance-variety of middle-distance swimmers covers more longer rather than sprint race distances. Therefore, at peak performance age, (top-) elite female 200 m swimmers show significantly slower sprint performances, i.e., 50 m (P < 0.001) and 100 m (P < 0.001), but not long-distance performances, i.e., 800 m (P = 0.99) and 1,500 m (P = 0.99). In contrast, (top-) elite female 800 m middle-distance runners show significantly slower performances in all their secondary race distances (P < 0.001). (Top-) elite female athletes specialize more than (highly-) trained athletes in both sports (P < 0.05). Conclusions: The comparison to track running and lower ranked swimmers, the early performance plateau towards senior age, and the maintenance of a large within-sport distance variety indicates that (top-) elite sprint swimmers benefit from greater within-sport specialization.

Interactive effects of sedimentary turbidity and elevated water temperature on the Pugnose Shiner (Miniellus anogenus), a threatened freshwater fish.

High turbidity and elevated water temperature are environmental stressors that can co-occur in freshwater ecosystems such as when deforestation increases solar radiation and sedimentary runoff. However, we have limited knowledge about their combined impacts on fish behaviour and physiology. We explored independent and interactive effects of sedimentary turbidity and temperature on the swimming activity and both thermal and hypoxia tolerance of the Pugnose Shiner (Miniellus anogenus, formerly Notropis anogenus), a small leuciscid fish listed as Threatened under Canada's Species at Risk Act (SARA). Fish underwent a 15-week acclimation to two temperatures (16°C or 25°C) crossed with two turbidities (~0 NTU or 8.5 NTU). Swimming activity was measured during the first 8 weeks of acclimation. Fish in warm water were more active compared to those in cold water, but turbidity had no effect on activity. Behavioural response to hypoxia was measured after 12 weeks of acclimation, as the oxygen level at which fish used aquatic surface respiration (ASR). Fish in warm water engaged in ASR behaviour at higher oxygen thresholds, indicating less tolerance to hypoxia. Turbidity had no effect on ASR thresholds. Finally, thermal tolerance was measured as the critical thermal maximum (CTmax) after 13-15 weeks of acclimation. Acclimation to warm water increased fish CTmax and Tag (agitation temperature) but reduced the agitation window (°C difference between Tag and CTmax) and thermal safety margin (°C difference between the acclimation temperature and CTmax). Furthermore, fish in warm, turbid water had a lower CTmax and smaller thermal safety margin than fish in warm, clear water, indicating an interaction between turbidity and temperature. This reduced thermal tolerance observed in Pugnose Shiner in warm, turbid water highlights the importance of quantifying independent and interactive effects of multiple stressors when evaluating habitat suitability and conservation strategies for imperilled species.

Mortality events associated with microsporidian, Spraguea sp., in White Trevally culture in Japan.

In 2021, White Trevally or Striped Jack cultured in the western part of Japan exhibited mild, but chronic mortalities from late September through early October. The cumulative mortality rate was approximately 0.02% per a net pen containing approximately 50,000 fish. Although the cumulative mortality rate was not high, most of the fish in net pens showed characteristic gross signs and an abnormal swimming behaviour. The body of diseased fish became pale and the yellow lines on the lateral sides of fish body became darken. In addition, silver lines along the dorsal fin became apparent. Loss of schooling behaviour was noted during the mortality event. In addition, affected fish became lethargic and failed to swim against current, or frequently stopped swimming and sank to the bottom of net pens after feeding. The goal of this study was to identify the cause of the mortality event. To achieve the goal, we used histopathology and metatranscriptome analysis. Histopathological examination revealed that xenoma of microsporidian were frequently observed in the nerve axon in the brain and spinal cord. Spores observed in the sections were stained with a fluorescent dye, Uvitex 2B, indicating those spores are microsporidian. The data from metatranscriptome analysis indicated that the microsporidian is Spraguea sp. The microsporidian was frequently detected from diseased fish with similar symptoms collected in the same region, suggesting that the microsporidian was highly associated with abnormal swimming behaviour of fish.

Jellyfish-Inspired Soft Robot Driven by Pneumatic Bistable Actuators.

Soft actuators offer numerous potential applications; however, challenges persist in achieving a high driving force and fast response speed. In this work, we present the design, fabrication, and analysis of a soft pneumatic bistable actuator (PBA) mimicking jellyfish subumbrellar muscle motion for waterjet propulsion. Drawing inspiration from the jellyfish jet propulsion and the characteristics of bistable structure, we develop an elastic band stretch prebending PBA with a simple structure, low inflation cost, exceptional driving performance, and stable driving force output. Through a bionic analysis of jellyfish body structure and motion, we integrate the PBA into a jellyfish-like prototype, enabling it to achieve jet propulsion. To enhance the swimming performance, we introduce a skin-like structure for connecting the soft actuator to the jellyfish-like soft robot prototype. This skin-like structure optimizes the fluid dynamics during jet propulsion, resulting in improved efficiency and maneuverability. Our study further analyzes the swimming performance of the jellyfish-like prototype, demonstrating a swimming speed of 3.8 cm/s (0.32 body length/s, BL/s) for the tethered prototype and 4.7 cm/s (0.38 BL/s) for the untethered prototype. Moreover, we showcase the jellyfish-like prototype's notable load-bearing capacity and fast-forward swimming performance compared to other driving methods for underwater biomimetic robots. This work provides valuable insights for the development of highly agile and fast responsive soft robots that imitate the subumbrellar muscle of jellyfish for efficient water-jet propulsion, utilizing skin-like structures to enhance swimming performance.

The Method but Not the Protocol Affects Lactate-Threshold Determination in Competitive Swimmers.

PURPOSE: The study validated variables corresponding to lactate threshold (LT) in swimming. Speed (sLT), blood lactate concentration (BLLT), oxygen uptake (VO2LT), and heart rate (HRLT) corresponding to LT were calculated by 2 different incremental protocols and validated in comparison with maximal lactate steady state (MLSS). METHODS: Ten competitive swimmers performed a 7 × 200-m front-crawl incremental "step test" with 2 protocols: (1) with 30-second rests between repetitions (short-rest incremental protocols) and (2) on a 5-minute cycle (swim + rest time, long-rest incremental protocols). Five methods were used for the assessment of sLT and corresponding BLLT, VO2LT, and HRLT: intersection of 2 lines, Dmax, modified Dmax, visual inspection, and intersection of combined linear and exponential regression lines. Subsequently, swimmers performed two to three 30-minute continuous efforts to identify speed (sMLSS) and physiological parameters corresponding to MLSS. RESULTS: Both protocols resulted in similar sLT and corresponding physiological variables (P > .05). Bland-Altman plots showed agreement between protocols (sLT, bias: -0.017 [0.002] m·s-1; BLLT, bias: 0.0 [0.5] mmol·L-1; VO2LT, bias: -0.1 [2.2] mL·kg-1·min-1; HRLT. bias: -2 [8] beats·min-1). However, sLT calculated by modified Dmax using short rest was higher compared with speed at MLSS (1.346 [0.076] vs 1.300 [0.101] m·s-1; P < .05). CONCLUSIONS: Calculated sLT, BLLT, VO2LT, and HRLT using all other methods in short-rest and long-rest incremental protocols were no different compared with MLSS (P > .05). Both 7 × 200-m protocols are valid for determination of sLT and corresponding physiological parameters, but the modified Dmax method may overestimate sLT.

Genus Carissa L.: a newly explored sustainable source of virulence inhibitors: a mini review.

Misuse of antibiotics led to the world wide spread of antimicrobial resistance threatening human lives. The notable resistance of bacterial cells to antibiotics and immune system is the difficulty associated with biofilm-linked illnesses. Natural products from plant origin with antibiofilm activity could provide more therapeutic activity with fewer adverse effects. Carissa L. is a potential drug candidate that can be considered as an agro-food waste sustainable virulence inhibitor source. This mini-review sheds light on recent studies dealing with the anti-virulence potential of Carissa species and its different mechanisms of action. The traced articles revealed that Carissa species exhibited potent antibiofilm, anti-quorum sensing, hyaluronidase inhibitory and anti-adhesion potentials, in addition to violacein, and swimming motility inhibition activities. Ursolic acid, oleanolic acid, and methyl oleanate are the main phytoconstituents of Carissa with claimed virulence inhibitory potentials. Carissa species are safe, valuable, and effective anti-virulence drugs suppressing pathogenicity when compared to conventional antibiotics.

Water safe Worcester: student-led drowning prevention in an adolescent underserved population.

Adolescents aged 15 to 19 years have the second highest fatal drowning rate of any age group, second only to toddlers aged 12 to 36 months. This risk is amplified in black, indigenous, and people of color (BIPOC), and those of low socioeconomic status. Worcester, MA is a diverse city with over 40% of residents identifying as BIPOC and 20% living below the poverty line. The city has multiple natural bodies of water available for recreation, putting Worcester residents, particularly adolescents, at high risk of drowning. It is known that swimming lessons provided to adolescents significantly improve their swimming skills, however many programs are tailored to young children and are not appropriate for adolescents. Students from the University of Massachusetts T.H. Chan Medical School (UMass Chan), in collaboration with community partners, developed a water safety and swim education program tailored to Worcester adolescents as a means for an age-appropriate swim experience and education, community engagement, and injury prevention. Water Safe Worcester (WSW) was established as a city-wide injury prevention program that included swim lessons offered by medical students at the Central Community Branch YMCA in Worcester, MA. Instructors included UMass Chan medical students, graduate students, and staff. Adolescent YMCA members were invited to participate in lessons free of charge. Lessons were 90 min and emphasized a 3-fold approach: (1) expand knowledge of water safety and what to do in an emergency, (2) increase swimming skills, and (3) reduce fear of water. The overall attendance for the 2023 spring and summer sessions offered was 73 students, including multiple swimmers who attended more than one session. A total of 12 volunteers participated, which included 9 first-year medical students, one PhD student, one research assistant, and one surgery resident from UMass Chan. WSW demonstrated promising outcomes during its swim education classes, suggesting that WSW is a successful model to promote water safety, reduce the risk of drowning, and expand access to life-saving skills to Worcester's at-risk adolescents. This program serves as a critical step toward health equity while also providing an avenue for public health and injury prevention exposure for medical students.