Outcome Of Competition Research Articles

The impact of long-haul travel and 13h time change on sleep and rest activity circadian rhythm in speed skaters during World Cup competitions.

Athletes frequently compete only a few days after long-haul travel. Longitudinal real-world data on athletes' sleep and sleep-wake cycle in competitive settings remain scarce. This study assessed the impact of a long-haul travel across ∼13 time zones on sleep patterns, rest-activity circadian rhythms (RAR), and their subsequent effects on neuromuscular function and race performance in the Canadian Short-Track Speed Skating Team. Nineteen athletes (24±4years, 11 women) travelled from Montréal (UTC-5) to Asia (UTC+8, UTC+9) for World Cup races between 2017 and 2019. Actigraphy data were collected before (Baseline) and during travel, during the stay in Asia (SIA), and during competition days. RAR were computed using cosinor analyses on accelerometry data with 24h phase periods. Countermovement jump height (CMJ) was measured in a subsample (n=10). Compared to baseline (7:08±0:53), athletes obtained less sleep during travel (6:16±1:27) and competition days (6:35±1:10), and more during SIA (7:32±0:46; time effect P<0.0001). Sleep efficiency and CMJ were greater in SIA than baseline (P=0.007 and P=0.0004, respectively). During SIA, sleep time increased by 9 min per night until the fifth day (P<0.0001), with a slight decrease in sleep efficiency (P=0.005) and an increase in CMJ (P<0.0001). For RAR, mean activity peaked on day 2, shifting from late evening to ∼15:00. Race performance was not different from other races of the same season (P>0.254). Our results demonstrated that, despite the possible sleep debt from the long-haul travel, athletes recovered within 5 days, highlighting their adaptability to manage sleep debt and jetlag without impacting competitive outcomes.

Attack efficiency in first league men’s volleyball for playing positions, according to the value level of the teams

Background and Study Purpose. The attack is a crucial technical element in scoring points in volleyball. This research aims to identify differences in attack efficiency and errors based on the value level of teams in the competitive system, considering different playing positions. Material and Methods. The analysis included 86 attacking players from the rosters of 12 teams in the men’s domestic first league. The distribution by positions was as follows: 37 outside hitters, 19 opposites, and 30 middle blockers. Statisticians from each team recorded the data using Data Volley software during three championship matches. For each player, the following parameters were interpreted: Attack Efficiency (E%), Error% (=), Blocked Attack% (/), Poor% (-), Blocked but Recovered% (!), Positive% (+), and Winning% (#). Attack efficiency was analyzed for each playing position across top teams (positions 1-4 in the final ranking), mid-level teams (positions 5-8), and lower-level teams (positions 9-12). Results. Across all three playing positions, top teams demonstrate higher percentages in attack efficiency, winning executions, and positive outcomes compared to average and lower-level teams. Top and average teams also have lower percentages of errors in attack executions. For the outside hitter position, no statistically significant superiority is observed between top and middle teams for any attack variable, indicating a balance in player performance. In the opposite hitter position, top and middle-level players show higher attack efficiency and direct point scores (Winning). They also have lower poor execution rates, despite the lack of statistical confirmation for superiority in many attack variables. Among all positions, top middle blockers exhibit a clear superiority over low-level teams across all attack variables. Conclusions. The findings of the study highlight the critical role of team value level in influencing attack efficiency and execution quality across different playing positions in volleyball. The results underscore the importance of strategic differentiation in training and game planning. This is especially crucial for teams aiming to optimize their performance. Coaches and trainers should focus on tailored approaches that address the specific strengths and weaknesses of each playing position. They should also consider the overall team value level in their strategies. This approach could lead to improved competitive outcomes and a more effective utilization of player potential across all levels of competition.

A Brief Analysis of The Economic Impact of Major Sporting Event on The Host City

The study of sports competition is a crucial field of research that comprises subjects such as economics, sociology, and other related fields. Scholars in this endeavour to tackle paramount questions with profound practical ramifications, which includes exploring the qualities and movements that underlie sports competition. Exploring the factors that influence sports competition outcomes and the ways in which these factors shape diverse competitive landscapes is a valuable and significant research area. This research examines the economic impact of major sports events on the host city. The aim of this research is to provide a thorough analysis of the economic consequences that follow from hosting such events. Through a synthesis of existing literature and empirical analysis, the research investigates the various facets of the economic impact of major sports events, encompassing employment, local commerce, tourism, and infrastructure development. The results indicate that such events can yield significant economic gains, ultimately promoting regional growth and development. However, a thorough analysis of the available evidence emphasises the importance of adopting a multidimensional viewpoint that takes into the account the social, cultural, and environmental ramifications. Despite the intricacies and constraints in accurately measuring the magnitude of the effects, this research ascertains that organising major sports events can generate favourable economic consequences for the locality. The results emphasise the significances of thorough analyses and additional research to enhance our comprehension of the economic implications of hosting such events.

Exposure to Lead (Pb) influences the outcomes of male-male competition during precopulatory intrasexual selection

Male-male competition is a component of Darwin’s theory of precopulatory intrasexual selection, where males compete for access to resources important for reproduction and successful males pass on traits that endow greater competitive ability to their offspring, thereby exaggerating the trait(s) over evolutionary time. Metals, such as lead (Pb) often occur in urban mangrove forests, where shore crabs reside, and being neurotoxic may cause sub-lethal effects on behaviour. In this study, we asked whether exposure to Pb influences the outcomes of male-male competition in the Semaphore crab, Heloecius cordiformis, thereby altering outcomes of intrasexual selection. Crabs were exposed to an environmentally relevant, and a behaviourally relevant, concentration of lead (i.e. Pb, 10 µg/L and 100 µg/L respectively) under laboratory conditions for 96 h and subsequently allowed to compete for burrow ownership in experimental arenas. Exposed crabs (100 µg/L) were less successful than control crabs in chela size-matched paired competitive interactions, spent less time in burrows and predominantly lost burrow ownership. Further, exposure to Pb contamination (both 10 µg/L and 100 µg/L) negated the chela size advantage in size-asymmetric competitive interactions. This contaminant-induced loss of size-related competitive advantage may result in relaxation in selection pressure on body size and smaller male carapace widths and especially male chela lengths in contaminated locations. Assessment of a range of locations in the wild found a consistent pattern of metal-associated size declines in more contaminated locations for males, but not for females.

Rapid Weight Changes and Competitive Outcomes in Muay Thai and Mixed Martial Arts: A 14-Month Study of 24 Combat Sports Events.

This study investigates the rapid weight loss (RWL) and rapid weight gain (RWG) of contest winners and losers from Muay Thai (MT) and mixed martial arts (MMA) events. The relationship between rapid weight change variables of males and females, and competitive success is also examined. Data from a weight management questionnaire was collected one day post-competition from 185 participants across 24 fight events, resulting in 263 responses (MMA: n = 78, MT: n = 185). Official and secondary weigh-in data were provided by the Combat Sports Commission. The results show that in MT, contest winners compared to losers had significantly greater RWL-7 days (5.9 ± 2.6% vs. 4.6 ± 2.7%, p = 0.01), RWG (6.2 ± 2.9% vs. 4.7 ± 2.8%, p = 0.003), and RWG/RWL ratio (108% [86-132%] vs. 86% [60-119%], p = 0.038), while no significant differences were observed for MMA. Mixed logistic regression models that controlled for age showed that a 1% increase in female RWL-24 h ([OR = 1.57, R2 = 0.105, p = 0.001]) was associated with a 1.6 times higher likelihood of winning compared to female athletes without this increase. We emphasise that associations do not imply causation, and it is possible that other factors which align with rapid weight change practices may impact the observed relationship. Nonetheless, MT contest winners show greater RWL, RWG, and RWG/RWL ratio than losers, and female rapid weight changes appear to be associated with competitive success in this cohort.

The effect of phosphorus, irradiance and competitor identity on the relative performance of invasive Chromolaena odorata

BackgroundResource competition is an important factor affecting the invasion success of alien plants, and environmental factors influence the competition outcomes between invasive and native plants. In this study, we explore the competitive pattern between invasive Chromolaena odorata and two native plant species under different phosphorus and irradiance levels.ResultsThe final biomass of each plant was regulated by both morphological and physiological traits. Invasive C. odorata did not always perform better than both native plants, and the competitive pattern between C. odorata and native plants was dependent on native competitor identity and environmental conditions. With competition, invasive C. odorata showed higher biomass (over 60%) than native Xanthium sibiricum under all treatments, but only showed higher biomass (about 20%) than native Eupatorium lindleyanum in normal irradiance treatments. The effect of phosphorus on competition depended on the irradiance level. Under normal irradiance, phosphorus addition increased (almost 10 times) the competitive index of invasive C. odorata; however, under shade irradiance, phosphorus addition decreased (40%) the competitive index of C. odorata.ConclusionThese results suggest that phosphorus, irradiance and native plant competitor together influence the relative performance of invasive C. odorata. In shade environment, selecting E. lindleyanum as competitor and increasing phosphorus level is an effective method for controlling the invasion of C. odorata.

Pterin-Based Red Coloration Predicts the Outcome of Male-Male Competition in Guinan Toad-Headed Lizard.

Animal coloration offers a unique opportunity to explore the evolutionary mechanisms underlying phenotypic diversity. Conspicuous coloration caused by pigments plays a crucial role in social signaling across multiple species by conveying information about individual quality, social ranks, or reproductive condition. Nevertheless, most previous studies have focused predominantly on colors produced by the exogenous pigments-carotenoids. Pterins are another prevalent group of conspicuous pigments, which can be produced endogenously and have received comparatively little attention. Whether pterin-based colors represent reliable signals remains elusive. The remarkable red ventrolateral coloration exhibited by males of the Guinan toad-headed lizard (Phrynocephalus guinanensis) in the Mugetan Desert presents an ideal model for investigating pterin-based coloration. Through electron microscopy and metabolomic identification, we discovered three types of pterin pigments within xanthophores. Integrating a series of morphological measurements and behavioral experiments, we found that this red coloration was not correlated with body size, bite force, and testosterone level, nor did females show a preference bias toward it. However, the red intensity predicted male-male competition outcomes, with deeper red males being more likely to emerge as winners. Our results indicated that the pterin-based coloration could convey information about male quality, suggesting its potential role in honest signaling, given the vital importance of pterin metabolism in physiological processes. This study provides a novel case into the understanding of pterin-based colors in animals.

VISTA: vision improvement via split and reconstruct deep neural network for fundus image quality assessment

AbstractWidespread eye conditions such as cataracts, diabetic retinopathy, and glaucoma impact people worldwide. Ophthalmology uses fundus photography for diagnosing these retinal disorders, but fundus images are prone to image quality challenges. Accurate diagnosis hinges on high-quality fundus images. Therefore, there is a need for image quality assessment methods to evaluate fundus images before diagnosis. Consequently, this paper introduces a deep learning model tailored for fundus images that supports large images. Our division method centres on preserving the original image’s high-resolution features while maintaining low computing and high accuracy. The proposed approach encompasses two fundamental components: an autoencoder model for input image reconstruction and image classification to classify the image quality based on the latent features extracted by the autoencoder, all performed at the original image size, without alteration, before reassembly for decoding networks. Through post hoc interpretability methods, we verified that our model focuses on key elements of fundus image quality. Additionally, an intrinsic interpretability module has been designed into the network that allows decomposing class scores into underlying concepts quality such as brightness or presence of anatomical structures. Experimental results in our model with EyeQ, a fundus image dataset with three categories (Good, Usable, and Rejected) demonstrate that our approach produces competitive outcomes compared to other deep learning-based methods with an overall accuracy of 0.9066, a precision of 0.8843, a recall of 0.8905, and an impressive F1-score of 0.8868. The code is publicly available at https://github.com/saifalkhaldiurv/VISTA_-Image-Quality-Assessment.

Phenology mediates direct and indirect interactions among co-occurring invasive plant species.

Why nonnative invasive plant species commonly co-occur, despite their competitive superiority and propensity to displace native species, remains a paradox in invasion biology. Negative interactions among competitively dominant invaders are potentially alleviated by two understudied mechanisms: seasonal priority effects, where phenological separation weakens the effect of competition on species with early phenology; and indirect facilitation, where competition between two species is mitigated by a third species. Although phenological separation has been speculated as a mechanism for explaining co-occurrence patterns of invasive plants, it has never been directly tested. In a greenhouse experiment, we tested the effect of phenological separation on direct and indirect interactions between three co-occurring invasive plant species found in the riparian forests of North America. These species have distinct natural phenological separation with reproduction in early spring (Ficaria verna), mid-spring (Alliaria petiolata), and late summer (Microstegium vimineum). When phenology was experimentally synchronized, direct pairwise interactions among invasive species were overwhelmingly negative, asymmetric, and unlikely to promote co-occurrence. However, increasing phenological separation generated seasonal priority effects, which weakened the effect of competition on species with early phenology. Furthermore, the addition of a third species generated indirect facilitative effects, which balanced competitive outcomes among the two weakest competitors. Based on these findings, we conclude that phenological separation modulates the strength of both seasonal priority effects and indirect facilitation within species interaction networks and may promote the co-occurrence of three common invasive species within this study system. We articulate how future studies can test the external validity of these findings in more complex environmental conditions and with a larger range of invasive plants.

Optimizing Water, Temperature, and Density Conditions for In Vitro Pea (Pisum sativum L.) Germination.

This study aimed to determine the optimal water, temperature, and density conditions, alongside antifungal treatments, for pea (Pisum sativum L.) germination in a laboratory setting, with implications for research, breeding, and microgreen production. Germination and early seedling growth were assessed across various temperatures (5 °C to 40 °C), water levels (0-14 mL per Petri dish), seed densities (5, 7, 9, and 11 seeds per Petri dish), and antifungal treatments (Hypo and Bordeaux mixture). The results indicated that optimal germination occurred between 15 °C and 25 °C, with peak performance at 25 °C. Water levels between 7 and 11 mL per 9 cm diameter Petri dish supported robust root and shoot development, while minimal water levels initiated germination but did not sustain growth. Five seeds per Petri dish was optimal for healthy development, whereas higher densities led to increased competition and variable outcomes. Antifungal treatments showed slight improvements in germination and growth, though differences were not statistically significant compared to controls. The study's novelty lies in its holistic approach to evaluating multiple factors affecting pea germination, offering practical guidelines for enhancing germination rates and seedling vigor. These findings support efficient and resilient crop production systems adaptable to varying environmental conditions, contributing to sustainable agriculture and food security. Future research should explore these factors in field settings and across different pea cultivars to validate and refine the recommendations.

Optical Flow as Spatial-Temporal Attention Learners.

Optical flow is an indispensable building block for various important computer vision tasks, including motion estimation, object tracking, and disparity measurement. To date, the dominant methods are CNN-based, leaving plenty of room for improvement. Inthiswork, we propose TransFlow, a transformer architecture for optical flow estimation. Compared to dominant CNN-based methods, TransFlow demonstrates three advantages. First, it provides more accurate correlation and trustworthy matching in flow estimation by utilizing spatial self-attention and cross-attention mechanisms between adjacent frames to effectively capture global dependencies; Second, it recovers more compromised information (e.g. occlusion and motion blur) in flow estimation through long-range temporal association in dynamic scenes; Third, it introduces a concise self-learning paradigm, eliminating the need for complex and laborious multi-stage pre-training procedures. The versatility and superiority of TransFlow extend seamlessly to 3D scene motion, yielding competitive outcomes in 3D scene flow estimation. Our approach attains state-of-the-art results on benchmark datasets such as Sintel and KITTI-15, while also exhibiting exceptional performance on downstream tasks, including video object detection using the ImageNet VID dataset, video frame interpolation using the GoPro dataset, and video stabilization using the DeepStab dataset. We believe that the effectiveness of TransFlow positions it as a flexible baseline for both optical flow and scene flow estimation, offering promising avenues for future research and development.

Post-Copulatory Sexual Selection in an Insect With High Levels of Mating Failure.

Sexual selection is not a single process. Instead, multiple processes of sexual selection can interact with respect to a given phenotype, in either reinforcing, independent, or conflicting directions. Here we consider how different processes of sexual selection interact in the seed bug Lygaeus simulans. This species is characterised by limited pre-copulatory sexual selection, but the potential for rather strong post-copulatory sexual selection. In particular, mating failure is common in this species, with around 40%-60% of copulations failing to result in the successful transfer of sperm. Mating failure is negatively correlated with female size, with smaller females being less likely to end up inseminated. We have recently argued that this pattern is best explained by cryptic male mate choice for large, more fecund females. Males therefore preferentially inseminate larger females. Here we explore how this potential cryptic male choice interacts with another component of post-copulatory sexual selection: sperm competition. We first manipulated male and female size variation, generating large and small, male and female, size classes. Using a visible mutant marker to assign paternity, we then double-mated females with males, in all combinations of male and female size. Our results showed that sperm competition outcomes were primarily driven by copulation duration, with longer copulations leading to greater paternity share for a male. We also confirmed that larger females are more likely to produce offspring than smaller females, as predicted by cryptic male choice for large females. This effect was again linked to copulation duration, with longer copulations less likely to lead to mating failure. While larger males tended to be more successful in sperm competition, especially if copulating second, female size had little effect on paternity, suggesting that cryptic male choice and sperm competition are acting relatively independently in this species.

A Parasite Plant Promotes the Coexistence of Two Annual Plants.

Consumers can influence the competitive outcomes of prey species in various ways. Modern coexistence theory predicts that consumers can promote prey coexistence by preferably targeting a competitively superior one, thereby reducing fitness differences. However, previous studies yielded mixed conclusions. In this study, we tested the hypothesis that a parasitic annual plant, Cuscuta campestris, facilitates the coexistence of two common annual plants. We performed field surveys and parasitism experiments to parameterize a plant competition dynamics model. The model suggested a competition-defence tradeoff: the legume Lespedeza striata was a better competitor than the grass Setaria faberi, while it was more susceptible to the parasite. Moreover, an empirical host-parasite dynamics model, extended from the plant competition model, predicted their coexistence within broad, biologically reasonable ranges of parameters. This work provides field evidence of the coexisting-promoting role of a parasitic plant, as caused by stabilising feedback between host and parasite densities.

Application of Sensor Technology in Wheelchair Sports for Real-Time Data Collection during Training and Competition and for Assessment of Performance Parameters: A Systematic Review and Future Directions.

This review reports on the use of sensors in wheelchair sports to monitor and analyze performance during match and training time. With rapid advancements in electronics and related technologies, understanding performance metrics in wheelchair sports is essential. We reviewed nine studies using various sensor types, including electric motors, inertial measurement units, miniaturized data loggers with magnetic reed switches, and smartphones with inbuilt accelerometers and gyroscopes, operating at frequencies from 8 Hz to 1200 Hz. These studies measured parameters such as angular and translational velocities, distance, number of starts/pushes, and other performance indicators in sports such as basketball, rugby, tennis, and racing. Despite differences in sport types and methodologies, most studies found sensor-derived data effective for assessment of performance. Future developments and research in this field should focus on multi-sensor systems that could provide real-time match analysis and deeper insights into performance metrics. Overall, sensor technologies show significant potential for improving wheelchair sport performance diagnostics, contributing to better athlete training and future wheelchair design, and enhancing competitive outcomes. This review emphasizes the need for continued innovation and standardization in applying sensor technologies in wheelchair sports.

Temporal variability in host availability alters the outcome of competition between two parasitoid species.

Variability in the availability of resources through time is a common attribute in trophic interactions, but its effects on the fitness of different consumer species and on interspecific competition between them are not clearly understood. To investigate this, we allowed two parasitoid species, Trichopria drosophilae and Pachycrepoideus vindemiae, to exploit Drosophila host pupae under different temporal variability treatments, either on their own or simultaneously. When tested individually (in the absence of interspecific competition), both parasitoid species had lower fitness when hosts were exposed for a short duration at high density than when exposed for a long duration at low density. When both parasitoid species exploited hosts simultaneously, interspecific competition significantly decreased the number of offspring for both parasitoid species. The outcome of this interspecific competition depended on host temporal variability, with T. drosophilae or P. vindemiae dominating in short and long host exposure treatments, respectively. These results can be explained by the combination of host availability and egg load of female adult parasitoids. When abundant hosts are provided for a short period, the ample mature eggs of the proovigenic T. drosophilae enable them to exploit hosts more efficiently than P. vindemiae, which is synovigenic. However, P. vindemiae is an intrinsically superior competitor and dominates when multiparasitism occurs. Multiparasitism is more frequent when hosts are at low levels relative to the egg load of the parasitoids. Our results clearly demonstrate that resource temporal availability can alter the outcome of competition between consumers with different reproductive traits.

Effects of water limitation and competition on tree carbon allocation in an Earth system modelling framework

Abstract Earth system models (ESMs) have a limited capacity to represent plant functional diversity and shifts in trait distributions. Approaches to improving the representation of this complexity in ESMs include (i) optimality‐based approaches that predict trait–environment responses and (ii) explicitly modelling coexistence and community assembly. These approaches are expected to converge only when optimality‐based approaches identify competitively dominant strategies, which often differ from strategies that maximize ecosystem functioning or fitness components in monoculture. We used two models, LM3‐PPA (a vegetation demographic model designed as an ESM component) and BiomeE (a computationally efficient analog for LM3‐PPA), to explore how water limitation affects carbon allocation strategies of canopy trees. We compared competitive allocation strategies and those that maximize biomass or productivity in monoculture. We did not explicitly model coexistence or community assembly. Rather, we used model experiments to identify competitive and maximizing strategies in a two‐dimensional trait space under different precipitation and mortality scenarios. At 10 eastern US locations, we simulated historical, wet and dry climate scenarios, novel drought and three different mortality scenarios (low, medium or high sensitivity to water deficit). For each site and scenario, we identified the competitive strategy and three maximizing strategies (maximum biomass, productivity or drought‐tolerance). Root: leaf ratios tended to increase and leaf area tended to decrease with increasing water stress (increasing water limitation and its effects on mortality). However, relative to maximizing strategies, competitive strategies shifted towards greater allocation to roots and leaves with increasing water stress. Competitive overinvestments (greater allocation to roots and leaves by competitive strategies compared with maximizing strategies) were robust across different modelling contexts, including vegetation parameter sets (Acer vs. Populus), models (LM3‐PPA vs. BiomeE) and uncalibrated vsersus calibrated BiomeE versions. Synthesis: The theoretical prediction that competitive and maximizing allocation strategies differ under water limitation is confirmed for a demographic model designed as an ESM component. Optimality‐based trait predictions can simplify representing trait diversity in ESMs but do not always correspond to competitive outcomes. Explicitly modelling coexistence and community assembly in ESMs is challenging but is likely the most general approach to representing trait diversity.

PORTRAIT OF TEACHING ENGLISH IN PRIMARY SCHOOL UNDER KURIKULUM MERDEKA

The changes in the national curriculum in Indonesia have been regular since the independence. It is an action taken to improve the quality of education given the demands of both era and society as well as a preparation of more competitive outcomes. This study concerns teachers' perceptions of the current curriculum (Kurikulum Merdeka). It is important to see how it is going in the practical field, particularly in teaching English in primary schools. This study employed a case study design where Six English teachers from six different schools in Kuningan, West Java, Indonesia took part as participants in the current study. They were interviewed in two modes, onsite and online, to share their views regarding the Merdeka curriculum implementation. The data from the interviews were analyzed through qualitative analysis. The result shows that both schools and policymakers have done several aspects regarding the implementation. Meanwhile, along with its implementation, the challenges exist including time allotment, students’ proficiency, and students' motivation, Therefore, the findings should be taken seriously, to improve the quality of teaching English at the primary level.

Pre and Post Competition Psychology and its Relationship with Competition Results in Lawn Bowl Disabilities Athletes in Asian Paragames 2022

This research purpose was investigated the psychology of disabilities athletes before and after the competition and the relationship with the results of the lawn bowl competition at the Asian Paragames 2022. The research method used is a survey. The 12 blind athletes (6 men and 6 women) participating in this study were aged 37.67±11.07 years, weight 68.58±10.13 kg, height 165.00±7.07 cm, and had 3.19±1.06 years of experience playing lawn bowls. Data analysis was carried out using paired t-test and regression analysis with significance at p&amp;lt;0.05. The results of the paired t-test revealed significant differences before and after the competition in athletic identity (p = 0.000), anxiety (p = 0.000), self-efficacy in sports (p = 0.000), expectations of success (p = 0.000), and mood profile (p = 0.000). The results of the regression analysis revealed that the regression model which included anxiety, athletic identity, expectations of success, self-efficacy in sports, and mood profile was significant for competition outcomes (F = 101.75, p = 0.000), with 99.92% of competition outcomes explained by variations in psychological variables (R square = 0.992). Based on the relationship, only anxiety shown a negative relationship to the competition results with a regression coefficient of -3.102 for anxiety-state and -0.723 for anxiety-trait. In conclusion, improvements are needed in athletic identity, self-efficacy, expectancy of success, and a positive mood profile to reduce the anxiety level before competition then improve competition performance better in lawn bowl athletes.

Combined effects of food quality and temperature on competitive interactions between small- and large-bodied cladoceran species

Competition is one of the main drivers of population dynamics of cladoceran species. According to the Size Efficiency Hypothesis, large-bodied cladocerans are superior competitors over small-bodied species because they are more effective filter-feeders and can consume a wider size spectrum of food particles. However, we hypothesized that food quality in terms of phosphorus (P) and/or polyunsaturated fatty acid (PUFA) content can alter competitive interactions, and these potential effects can be modified by temperature. Since large-bodied cladocerans are more vulnerable to poor food quality and are regarded as less adaptive to high temperatures, we hypothesized that large-bodied species would be superior competitors at low temperature and/or high food quality, while small-bodied cladocerans would be competitively superior at enhanced temperature and/or poor food quality. To verify this hypothesis, we conducted laboratory experiments with the small-bodied D. longispina and large-bodied D. magna fed with three different types of food: (1) P-poor and PUFA-rich green algae (low phosphorus or LP-treatment), (2) PUFA-poor-cyanobacteria treatment (CYANO) and (3) P-rich and PUFA-rich green algae (high phosphorus or HP-treatment) at 18°C and 24°C. We found that D. magna had a stronger suppressive competitive effect on D. longispina in all food quality and temperature treatments. Nevertheless, food quality and temperature modified competitive interactions between the small- and large-bodied Daphnia. In HP and CYANO, both Daphnia species were more strongly suppressed by competitor presence at high than low temperatures, whereas in LP mutual suppression was relatively weaker at higher temperatures. This phenomenon was attributed to higher requirement for P at enhanced temperature which created constraints for population growth thus decreasing competitive interactions at higher temperatures. Mutual competitive suppression in CYANO was weaker than in the HP treatment although cyanobacteria had the greatest negative impact on the abundance of both Daphnia species. In general our results show that the outcome of competition between large and small-bodied cladoceran species was not affected by food quality and/or temperature, yet, these factors markedly altered competitive interactions between species.

Arbuscular mycorrhizal fungi equalize differences in plant fitness and facilitate plant species coexistence through niche differentiation.

Mycorrhizal fungi are essential to the establishment of the vast majority of plant species but are often conceptualized with contradictory roles in plant community assembly. On the one hand, host-specific mycorrhizal fungi may allow a plant to be competitively dominant by enhancing growth. On the other hand, host-specific mycorrhizal fungi with different functional capabilities may increase nutrient niche partitioning, allowing plant species to coexist. Here, to resolve the balance of these two contradictory forces, we used a controlled greenhouse study to manipulate the presence of two main types of mycorrhizal fungus, ectomycorrhizal fungi and arbuscular mycorrhizal fungi, and used a range of conspecific and heterospecific competitor densities to investigate the role of mycorrhizal fungi in plant competition and coexistence. We find that the presence of arbuscular mycorrhizal fungi equalizes fitness differences between plants and stabilizes competition to create conditions for host species coexistence. Our results show how below-ground mutualisms can shift outcomes of plant competition and that a holistic view of plant communities that incorporates their mycorrhizal partners is important in predicting plant community dynamics.