Body and Fat mass are not Regulated, Controlled, or Defended: An introduction to the Invisible Hand' and 'Competition' Models of Metabolism

This paper presents two inter-dependent frameworks for understanding the etiology of obesity and the regain of body and fat mass after weight loss. The 'Invisible Hand of Metabolism' illustrates how physiologic states such as body and fat mass and blood glucose levels arise from the unregulated, uncontrolled, yet competitive behavior of trillions of semi-autonomous cells. The 'Competition Model of Metabolism' is an explanatory (mechanistic) framework that details how organismal and cell-specific behaviors generate the apparent stability of physiologic states despite metabolic perturbations (e.g., weight-loss and exercise). Together, these frameworks show that body and fat mass and blood glucose levels are not regulated, controlled, or defended but emerge from the complexity and functional plasticity of competitive cellular relations. Therefore, we argue that the use of abstract constructs such as 'regulation', 'control', 'glucostats', 'adipostats', and 'set-/settling-points' hinders the understanding of obesity and cardiometabolic diseases in human and nonhuman mammals.

Overshadowing, but not Relative Validity, Between the Elements of an Outcome During Human Associative Learning

Overshadowing and relative validity constitute two phenomena that inspired the development of the Rescorla-Wagner model in 1972. They demonstrate that cues will interact with one another for an association with the presence or absence of an outcome. Here, three experiments sought to explore whether these two effects extended to outcomes using a food allergist paradigm with human participants. In Experiment 1 (overshadowing) participants received trials in which a cue was followed by a compound of two outcomes (A-O1O2). Test trials revealed that participants learned less about the A-O2 association than they did between a control cue C, which had been paired with O2 in isolation (C-O2) in training - thus demonstrating an outcome overshadowing effect. In Experiment 2 (relative validity) participants received true discrimination trials, in which A was paired with an O1O3 compound and B was paired with an O2O3 compound, and pseudo discrimination trials, in which C and D were paired on 50% of the trials with an O4O6 compound and on the remaining trials with an O5O6 compound. Consequently, O3 is less well predicted by A and B relative to O1 and O2, whereas O6 is equally well predicted by C and D relative to O4 and O5. Despite the relative validity of A and B for O3 being less than the relative validity of C and D for O6, the ratings of A and B for O3 were the same as C and D for O6. This failure to observe an outcome relative validity effect was reproduced in Experiment 3, which replicated Experiment 2, but with an adjustment made to the number of training trials given to participants. These results are discussed in terms of a real-time development of the Rescorla-Wagner model provided by Wagner (1981).

Kinetic modeling of the adsorption and desorption of metallic ions present in effluents using the biosorbent obtained from Syagrus romanzoffiana

In this study, the kinetic mechanism of adsorption and desorption, as well as the equilibrium isotherms, of four metallic ions (Cd²⁺, Cu²⁺, Ni²⁺, and Zn²⁺) mono and multicomponent were investigated. The biosorbent used was produced from Jerivá (Syagrus romanzoffiana-commonly known as queen palm) coconut. A kinetic model that considers macropore diffusion as a control step was solved. The finite volume method was used in the discretization of the equations, and the algorithm was implemented in the Fortran programming language. The equilibrium time for monocomponent adsorption was 5 min; for the multicomponent tests, equilibrium occurred instantly (less than 2 min of adsorption). The pseudo-second-order model presented the lowest mean of the sum of normalized errors (SNE) and represented the experimental data of mono and multicomponent adsorption and desorption. Single and multicomponent Langmuir model represented the adsorption isotherms. The maximum capacity of adsorption of metallic ions, both mono and multicomponent, was higher for copper, and the multicomponent adsorption proved to be antagonistic; the presence of co-ions in the solution reduced the removal of metals due to competition between these contaminants. The capture preference order was justified by the physicochemical properties of the ions, such as electron incompatibility and electronegativity. All these situations justified the maximum adsorption of Cu²⁺, followed by Zn²⁺, Cd²⁺, and Ni²⁺ in the mixture.

Substrate inhibition can produce coexistence and limit cycles in the chemostat model with allelopathy

In this work, we consider a model of two microbial species in a chemostat in which one of the competitors can produce a toxin (allelopathic agent) against the other competitor, and is itself inhibited by the substrate. The existence and stability conditions of all steady states of the reduced model in the plane are determined according to the operating parameters. With Michaelis-Menten or Monod growth functions, it is well known that the model can have a unique positive equilibrium which is unstable as long as it exists. By including both monotone and non-monotone growth functions (which is the case when there is substrate inhibition), it is shown that a new positive equilibrium point exists which can be stable according to the operating parameters of the system. This general model exhibits a rich behavior with the coexistence of two microbial species, the multi-stability, the occurrence of stable limit cycles through super-critical Hopf bifurcations and the saddle-node bifurcation of limit cycles. Moreover, the operating diagram describes some asymptotic behavior of this model by varying the operating parameters and illustrates the effect of the inhibition on the emergence of the coexistence region of the species.

Effects of service attributes and competition on electronic word of mouth: an elaboration likelihood perspective

The management of electronic word of mouth (eWOM) is critical in e-commerce. In this study, on the basis of the elaboration likelihood model (ELM), we constructed a model of factors influencing eWOM by dividing merchants' attributes into the central and peripheral routes, which correspond to consumers' systematic and heuristic cognitive modes respectively. We then tested the developed model by using a cross-sectional data set. The results of this study indicate that the degree of competition faced by merchants has a significant negative association with eWOM. Moreover, price level and location moderate the relationship between competition and eWOM. The services of reservation and group buying have positive associations with eWOM. This research has three main contributions. First, we explored the effect of competition on eWOM. Second, we validated the feasibility of applying the ELM to the catering industry by dividing merchant attributes into the central and peripheral routes; this approach is consistent with systematic and heuristic cognitive theories. Finally, this research provides practical suggestions for eWOM management in the catering industry.

The neuroscience of social comparison and competition

The study of competition from a social comparison perspective offers valuable insights into the neuroscience of social judgment and decision making under uncertainty. When engaging in social comparison, individuals seek and assess information about similarities or differences between others and themselves, in large part to improve their self-evaluation. By providing information about one's relative position, abilities, outcomes, and more, social comparisons can inform competitive judgments and decisions. People reasonably turn to social comparisons to reduce uncertainty before, during, and after competition. However, the extent to which they do so and the behavioral consequences of social comparisons often fail to match the potential benefits of improved self-evaluation. An examination of the developing neuroscience of social comparison and competition in light of the behavioral evidence reveals numerous questions that merit further investigation.

Age effects in second language acquisition: Expanding the emergentist account

In 2005, Science magazine designated the problem of accounting for difficulties in L2 (second language) learning as one of the 125 outstanding challenges facing scientific research. A maturationally-based sensitive period has long been the favorite explanation for why ultimate foreign language attainment declines with age-of-acquisition. However, no genetic or neurobiological mechanisms for limiting language learning have yet been identified. At the same time, we know that cognitive, social, and motivational factors change in complex ways across the human lifespan. Emergentist theory provides a framework for relating these changes to variation in the success of L2 learning. The great variability in patterns of learning, attainment, and loss across ages, social groups, and linguistic levels provides the core motivation for the emergentist approach. Our synthesis incorporates three groups of factors which change systematically with age: environmental supports, cognitive abilities, and motivation for language learning. This extended emergentist account explains why and when second language succeeds for some children and adults and fails for others.

How do International Olympic Sport Federations innovate? The use of crowdfunding and the impact of COVID-19

The purpose of this study was to contribute to the understanding of innovation and crowdfunding of International Olympic Sport Federations (IFs), which are the world governing bodies of their respective sports. Three research questions were addressed: the perceptions of the IFs on the implementation of their innovation programmes during the last four years (2016-2020), the impact of COVID-19 on the IFs capability to innovate, and the crowdfunding strategies of the IFs. A mixed method combining qualitative and quantitative approaches was used. An online semi-structured questionnaire which included an open answer section was completed by IFs executives (n = 22) and an analysis of the information provided by IFs through various content sources was conducted. Results showed that IFs with less funding had a significantly more innovative approach that their counterparts, that the perception of the impact of COVID-19 on the innovative capability was not unanimous, that they identified sport-specific programmes as the most innovative of all initiatives delivered during the pandemic, and that crowdfunding projects were implemented in their sport but mostly at individual and local levels. From a research perspective, since this is the first study that investigates the innovation and crowdfunding strategies of IFs, future directions include the need for further research with national and regional federations on these topics. Practical implications are suggested for IFs to deliver innovative programmes to satisfy their stakeholder needs and to consider new funding methods such as crowdfunding as part of their strategies.

(How) is COVID-19 reframing interaction between the NHS and private healthcare?

In March 2020 a 'major deal' was struck between the National Health Service (NHS) and private healthcare sector to facilitate 'crisis' and 'continuity' responses to COVID-19. A further deal was struck in January 2022 to support the NHS in tackling the Omicron variant, suggesting that the pandemic was evolving, rather than definitively over. The legal basis for these deals was a Public Policy Exclusion Order, a temporary relaxation mechanism in UK competition law defined by a 'disruption period'. In a global pandemic, the 'healthcare disruption period' might be considered to be of a different scope and nature to short-term disturbances experienced in other sectors, such as groceries. This article examines the Public Policy Exclusion Orders issued in respect of health services in England and Wales, and the Collective Agreements notified under these between March 2020 and March 2021, and again in March 2022. Amid ongoing tensions surrounding 'NHS privatisation', this enables a timely analysis of whether the underlying relationship between the NHS and private healthcare may be changing in response to COVID-19, and how considerations of ethical frameworks are also relevant to this aspect of the pandemic response.

Cutting height as a competition control factor in teak (Tectona grandis L.f) plantations in southern Benin

The effect of stump sprouts on the growth of trees in the main plantation under system of even-aged forest was investigated in this study. In this context, eight plantations taking into account the age, the number of thinning and the type of soil were selected. In order to assess the practices related to cutting height, a survey was carried out in each plantation. In each plantation, at least, two square plots measuring 50 × 50 m (one containing trees with less stump sprouts and the other containing trees with stump sprouts) were installed. The density of stump sprouts and filler trees had a detrimental effect on the growth of trees in the main plantation. Competition for resources was the main cause. The density of stumps and those of filler trees within a radius of 5 m around each future tree were estimated at 3 stumps and 3 filler trees respectively. The distance between the future trees and the stump sprouts or the filler trees was estimated at around 3 m. The search for an appropriate cutting level, spacing of trees and compliance with recommendations related to silvicultural practices are among other solutions to limit this competition.

Case Studies in the Assessment of Microbial Fitness: Seemingly Subtle Changes Can Have Major Effects on Phenotypic Outcomes

Following the completion of an adaptive evolution experiment, fitness evaluations are routinely conducted to assess the magnitude of adaptation. In doing so, proper consideration should be given when determining the appropriate methods as trade-offs may exist between accuracy and throughput. Here, we present three instances in which small changes in the framework or execution of fitness evaluations significantly impacted the outcomes. The first case illustrates that discrepancies in fitness conclusions can arise depending on the approach to evaluating fitness, the culture vessel used, and the sampling method. The second case reveals that variations in environmental conditions can occur associated with culture vessel material. Specifically, these subtle changes can greatly affect microbial physiology leading to changes in the culture pH and distorting fitness measurements. Finally, the last case reports that heterogeneity in CFU formation time can result in inaccurate fitness conclusions. Based on each case, considerations and recommendations are presented for future adaptive evolution experiments.

Analysis and prediction of athlete's anxiety state based on artificial intelligence

Obtaining athletes' anxiety accurately and regulating their psychological state helps improve their competitive performance. Therefore, this article uses a hierarchical clustering algorithm to identify the sources of stress of track and field athletes. A novel and efficient hierarchical clustering algorithm is proposed in this article. The algorithm consists of two stages: dividing and agglomerating. In the dividing stage, the initial data set is taken as a class and subclasses more than the actual number of clusters are obtained through multiple dividing. In the agglomerating phase, the subclasses divided during the dividing process are merged into the correct class. In addition, we construct an analysis model of athletes' anxiety state based on the radial basis function (RBF) model, where athletes' anxiety is divided into three categories: physical condition anxiety, competition state and cognitive state. The proposed model is trained from the official website of the China Track and Field Association. The athletes' information from 500 samples was arranged to form the sample database of athletes' data. The implicit unit center, function width and connection weight record the characteristics of various sports anxiety states. Then we used the Bayesian and Lagrange models as comparative models for evaluating the psychological state. Precision and efficiency were used for evaluation indexes. The proposed model's results are much better in accuracy and time than those of the Lagrange and Bayesian models. The outcome of the proposed research can provide a reasonable basis for the decision-making of stress relief for track and field athletes.

Interactions between carnivore species: limited spatiotemporal partitioning between apex predator and smaller carnivores in a Mediterranean protected area

BACKGROUND

There is need of information on ecological interactions that keystone species such as apex predators establish in ecosystems recently recolonised. Interactions among carnivore species have the potential to influence community-level processes, with consequences for ecosystem dynamics. Although avoidance of apex predators by smaller carnivores has been reported, there is increasing evidence that the potential for competitive-to-facilitative interactions is context-dependent. In a protected area recently recolonised by the wolf Canis lupus and hosting abundant wild prey (3 ungulate species, 20-30 individuals/km², together), we used 5-year food habit analyses and 3-year camera trapping to (i) investigate the role of mesocarnivores (4 species) in the wolf diet; (ii) test for temporal, spatial, and fine-scale spatiotemporal association between mesocarnivores and the wolf.

RESULTS

Wolf diet was dominated by large herbivores (86% occurrences, N = 2201 scats), with mesocarnivores occurring in 2% scats. We collected 12,808 carnivore detections over > 19,000 camera trapping days. We found substantial (i.e., generally ≥ 0.75, 0-1 scale) temporal overlap between mesocarnivores-in particular red fox-and the wolf, with no support for negative temporal or spatial associations between mesocarnivore and wolf detection rates. All the species were nocturnal/crepuscular and results suggested a minor role of human activity in modifying interspecific spatiotemporal partitioning.

CONCLUSIONS

Results suggest that the local great availability of large prey to wolves limited negative interactions towards smaller carnivores, thus reducing the potential for spatiotemporal avoidance. Our study emphasises that avoidance patterns leading to substantial spatiotemporal partitioning are not ubiquitous in carnivore guilds.

Physical evidence of direct antagonistic interactions between trematodes in the host gut: the kiss of death?

Although within-host competition among parasites if often assumed to occur based on statistical patterns, actual physical evidence of direct antagonistic interactions between parasites, either intraspecific or interspecific, is very rare. Here, we report such evidence between and within two species of hemiurid trematodes infecting the deep-sea grenadier fish Coryphaenoides subserrulatus. We found pairs of worms attached together, with one worm using its ventral sucker against another worm, and sucking out a large protuberance on the victim. We also found single worms showing clear signs of past attacks. There was no evidence that these interactions were more common at high intensities of infection, where the conditions would be expected to be more conducive to competitive interactions. Our findings provide evidence that trematodes may cause some harm to co-occurring individuals, suggesting a direct form of interference competition among intestinal helminths.

An entomopathogenic fungus exploits its host humoral antibacterial immunity to minimize bacterial competition in the hemolymph

BACKGROUND

The insect hemolymph (blood-equivalent fluid), composed of a large number of hemocytes (blood cells) and a variety of soluble immune effectors, is hostile for pathogens including fungi. In order to survive in the insect hemocoel (body cavity), the entomopathogenic fungus (EPF) has evolved two classical coping strategies, namely evasion and suppression of the host immune reactions. However, it remains unclear whether EPF has other ways of coping with host immunity.

RESULTS

In this study, we demonstrated that Metarhizium rileyi (an EPF) infection by injection of blastospores into the hemocoel enhanced the plasma antibacterial activity of cotton bollworm (Helicoverpa armigera), which was partially due to the enhanced expression of antimicrobial peptides (AMPs). The early stage of M. rileyi infection induced the translocation of gut bacteria into the hemocoel, where they were subsequently cleared due to the enhanced plasma antibacterial activity. Further, we showed that the enhanced plasma antibacterial activity and AMP expression were attributable to M. rileyi but not the invasive gut bacteria (opportunistic bacteria). Elevated ecdysone (major steroid hormone in insects) levels in the hemolymph at 48 h post-M. rileyi infection might contribute to the enhanced expression of AMPs. The fungus-elicited AMPs, such as cecropin 3 or lebocin, exhibited potent inhibitory activity against the opportunistic bacteria but not against hyphal bodies. In addition, the opportunistic bacteria competed with hyphal bodies for amino acid nutrients.

CONCLUSIONS

M. rileyi infection induced the translocation of gut bacteria, and then the fungi activated and exploited its host humoral antibacterial immunity to eliminate opportunistic bacteria, preventing them from competing for nutrients in the hemolymph. Unlike the classical strategies, EPF utilizes to evade or suppress host immunity, our findings reveal a novel strategy of interaction between EPF and host immunity. Video Abstract.

Synaptic logistics: Competing over shared resources

High turnover rates of synaptic proteins imply that synapses constantly need to replace their constituent building blocks. This requires sophisticated supply chains and potentially exposes synapses to shortages as they compete for limited resources. Interestingly, competition in neurons has been observed at different scales. Whether it is competition of receptors for binding sites inside a single synapse or synapses fighting for resources to grow. Here we review the implications of such competition for synaptic function and plasticity. We identify multiple mechanisms that synapses use to safeguard themselves against supply shortages and identify a fundamental neurologistic trade-off governing the sizes of reserve pools of essential synaptic building blocks.

Competition and firm recovery post-COVID-19

This paper examines the impact of the COVID-19 crisis on the reallocation of economic activity across firms and whether this reallocation depends on the competition environment. The paper uses the World Bank's Enterprise Surveys COVID-19 Follow-up Surveys for about 8000 firms, including both small and large firms, in 23 emerging and developing countries in Europe and Central Asia, matched with 2019 Enterprise Surveys data. It finds that during the COVID-19 crisis, smaller firms were hit harder, and economic activity was reallocated toward firms with higher pre-crisis labor productivity. Countries with a strong competition environment experienced more reallocation from less productive to more productive firms than countries with a weak competition environment. The evidence also suggests that reallocation from low- to high-productivity firms during the COVID-19 crisis was stronger compared with pre-crisis times. Finally, the analysis shows that government support measures implemented in response to the crisis may have adverse effects on competition and productivity growth since support went to less productive and larger firms, regardless of their pre-crisis innovation.

Injury surveillance during elite women's national boxing championship in India

Background

Injury surveillance is the cornerstone of any prevention program. However the same pertaining to women's boxing is meager. We hence intended to analyse the incidence, pattern and characteristics of injuries in female boxers during the 4th Elite Women's National Boxing Championship, 2019, in India.

Methods

A total of 235 female Indian boxers participated in the tournament. Injuries from the competition injury database maintained in accordance with the injury code proposed by the Australian Sports Injury Data Dictionary were compiled to observe the pattern and analysed. The outcomes measured were incidence in terms of injury rate and injury risk and injury pattern in terms of site, nature, mechanism, severity and time of injury.

Results

The injury rate was observed to be 43.98 injuries per 1000 athlete bouts of exposure (95% confidence interval [CI]: 33.71-54.07) and 293.21 injuries per 1000 athlete hours of competition (95% CI: 225.94-360.47). The most commonly injured site was head, face and neck regions. Most injuries were bruises/contusions followed by cuts and epistaxis. No concussions were reported.

Conclusion

This study observed that women are less prone to injuries than their male counterparts, even though a logical comparison is difficult because of the lack of data and standardization in women's boxing.

Analysis on trade-in strategy of manufacturers competing with informal recycling enterprises

Considering the competition of informal recycling enterprises in the waste and old product recycling market, this paper analyzes the trade-in strategy of manufacturers and discusses the effect of implementing trade-in on the competition in the recycling market by comparing changes in recycling market shares, recycling prices, and profits before and after the implementation of a trade-in program. Without a trade-in program, manufacturers are always in an inferior position in the competition with informal recycling enterprises in the recycling market. With the implementation of a trade-in program, the recycling prices provided by manufacturers and shares of recycling market of manufacturers not only increase with the earnings of processing a unit old product, but also increase with the total profit margin of sales of new products and recycling of old products. The implementation of a trade-in program can enhance the competitiveness of manufacturers in their competition with informal recycling enterprises, causing manufacturers to obtain more shares and profits in the recycling market, and promoting the healthy and sustainable development of manufacturers in the sale of new products and the recycling of old products.

Does regional species diversity resist biotic invasions?

The role of regional species diversity in large-scale species invasions has been largely controversial. On the one hand, it has been proposed that diversity may facilitate invasion ("diversity begets diversity") because regions with higher diversity may indicate favorable conditions for many more species. On the other hand, high diversity may indicate high levels of niche occupation, thus making it more difficult for new species to invade. In the past, invasion biologists have evaluated how regional native and exotic richness are related. Here, we test whether the range size of exotic species may be constrained by regional native richness using plant data from three continental regions in the Northern Hemisphere, i.e., Europe, Eastern Asia, and North America. We found that regional native plant diversity is inversely related to the range size of exotic species. This result may be due to stronger species interactions such as competition in species-rich habitats that limit the establishment and spread of exotic species.

A novel mechanism measurement of predator interference in predator-prey models

A characteristic of ecosystems is the existence of manifold of independencies which are highly complex. Various mathematical models have made considerable contributions in gaining a better understanding of the predator-prey interactions. The main components of any predator-prey models are, firstly, how the different population classes grow and secondly, how the prey and predator interacts. In this paper, the two populations' growth rates obey the logistic law and the carrying capacity of the predator depends on the available number of prey are considered. Our aim is to clarify the relationship between models and Holling types functional and numerical responses in order to gain insights into predator interferences and to answer an important question how competition is carried out. We consider a predator-prey model and a two-predator one-prey model to explain the idea. The novel approach is explained for the mechanism measurement of predator interference through depending on numerical response. Our approach gives good correspondence between an important real data and computer simulations.

Explanations for variations in hospital expenditures among four large California counties

OBJECTIVE

To investigate competing explanations for why Medicare Fee for Service (FFS) and private sector payments lead to hospital cost variations in Californian counties.

DATA SOURCES

Ratios of private to Medicare hospital costs were obtained from state-based all-payer claims databases. Demographics were estimated from the U.S. Census Bureau and the California Health Interview Survey. Medicaid and Medicare spending was obtained from Kaiser Family Foundation. Medicare Advantage enrollment was obtained from the California Department of Health Care Services and market consolidation was estimated using the Herfindahl-Hirschman Index (HHI).

STUDY DESIGN

Per capita costs, demographics, Medicaid and Medicare spending, Medicare Advantage enrollment, and HHI scores were compared for San Francisco (SF), Sacramento, Los Angeles (LA), and San Diego (SD).

PRINCIPAL FINDINGS

LA hospitals had the lowest per capita private insurer costs, but the highest Medicare FFS costs. The findings might be explained by a lower HHI for LA, indicating a more competitive market, than SD, SF, and Sacramento.

CONCLUSIONS

Medicare FFS hospital costs do not provide an accurate representation of health care spending in Californian counties. In more competitive markets, private insurance companies can negotiate lower prices, while oversupply may allow facilities to increase volume in Medicare FFS.

Food Provision at the Olympic Games in the New Millennium: A Meta-narrative Review

BACKGROUND AND OBJECTIVE

The objective of this meta-narrative review was to identify, organise and map the literature on food provision and nutrition support at the summer and winter Olympic and Paralympic Games (OPG)  and similar major competition events over the past 21 years. This builds on a comprehensive update of a previous historical review of the evolution of food provision at the summer Olympic Games up until 2000 and considers contemporary issues such as the global pandemic and sustainability goals.

METHODS

A range of sources included primary research and review articles, edited book chapters, theses, conference papers or abstracts, International Olympic Committee reports, Organising Committees' food vision and post-Games reports, independent professional reports, and media and periodicals including magazines and trade journals. The search strategy included four steps: a database search that complied with Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews criteria, a search of the Olympic Studies Centre, a review of reference lists for unpublished sources, and a Google search for additional media reports. The researchers followed an iterative process where emerging narratives were discussed, recorded and refined as data were extracted.

RESULTS

The data from 229 records were extracted into a spreadsheet and grouped according to the type of evidence and specific event, then presented chronologically to give a perspective on the development of food provision and nutrition support. Eleven narratives emerged from the data extraction: 'description of meals, menus and food', 'vision of the food provision', 'food safety', 'catering company involvement', 'sponsorship or contracts with food companies', 'athlete perspective', 'stakeholder perspective', 'athlete food intake,' 'nutrition input in food provision', 'food environment' and 'sustainability'.

CONCLUSION

Results suggest that athletes' dining expectations, organising committee budgets, expert input and current global trends have led to food delivery changes. The OPG food environment has the capacity to positively influence the dietary choices of athletes and teams, while evolving to meet contemporary global challenges such as COVID-19 and sustainability targets.

Caution with competitive gamification in medical education: unexpected results of a randomised cross-over study

BACKGROUND

To intrinsically motivate students in the long term, longitudinal e-learning systems combined with repeated testing and competitive gamification seem promising. The effects of this approach have never been closely examined in the field of evidence-based medicine. The authors investigated if a simple, competitive learning application enhances students' risk competence and intrinsic motivation.

METHODS

Participants were 5.-9. semester medical students (n = 48), recruited in an elective evidence-based medicine subject and randomly distributed to two groups (group 1: n = 23; group 2: n = 25). Both accessed a competitive evidence-based medicine quiz game. Following a cross-over design, each group practiced with one of two thematically different questionnaires A or B, before the allocation switched after one month. To analyse whether there was a measurable learning effect in the practiced topics, a paired t-test was performed with quantitative data from 3 e-tests. Students further reported their experience in evaluation surveys.

RESULTS

Students' improvements in e-test scores after training with the corresponding topics in the learning application can be attributed to chance. Even though the majority enjoyed playing and felt motivated to study, they invested a minimum of time and rejected competition.

CONCLUSION

The authors found no evidence for benefits of the investigated learning programme on students' risk competence or on their internal motivation. The majority disapproved the competitive concept, indicating adverse side effects of the applied gamification element. To intrinsically motivate more students, prospective learning programmes should favour complex and collaborative programmes over simple and competitive ones.

Diel niche partitioning of a plant-hummingbird network in the Atlantic forest of Brazil

Niche partitioning is an important mechanism that allows species to coexist. Within mutualistic interaction networks, diel niche partitioning, i.e., partitioning of resources throughout the day, has been neglected. We explored diel niche partitioning of a plant-hummingbird network in the Brazilian Atlantic forest for nine months. To evaluate diel patterns of hummingbird visits and nectar production, we used time-lapse cameras on focal flowers and repeated nectar volume and concentration measures, respectively. Additionally, we measured flower abundance around focal flowers and flower morphological traits. We did not observe diel partitioning for either hummingbirds or plants. Instead, hummingbirds appeared to specialize in different plant species, consistent with trophic niche partitioning, potentially resulting from competition. In contrast, plant species that co-flowered and shared hummingbird visits produced nectar during similar times, consistent with facilitation. Our focus on the fine-scale temporal pattern revealed that plants and hummingbirds appear to have different strategies for promoting co-existence.