Background: The ability to solve complex challenges facing the food system is an increasingly important skill for undergraduate students entering into the global workforce. However, the curriculum tools to enhance systems thinking in the undergraduate agricultural and natural resource classroom are limited, specifically related to food systems education. Methods: The current study explored the use of hypothetical case scenarios in a teaching curriculum related to the seafood industry, in order to determine the use of these tools as a mechanism for increasing undergraduate students’ systems-thinking capacity. The mixed-method study used a survey and focus groups. Results indicated that participants’ understanding of, and capacity for, using systems thinking to reason through complex scenarios increased during the mixed-method educational intervention. Participants stated the experience helped them learn more about their own patterns of thinking, created transformational learning moments through dissonance, helped them learn about the unintended consequences of decision-making, and increased their understanding of system complexity. Conclusions: The implications of using hypothetical case scenarios in the food system education classroom are explored. Topics within agricultural and food systems education are complex, compounded by the information-dense environment in which students and the public find themselves daily . AdditioSystems thinking, related to complex systems learning, is an increasingly popular learning outcome within science education . IntegraOne of the primary challenges, however, for instructors implementing SSI-related content, such as systems thinking, in the classroom, is a lack of pedagogical tools and professional development competencies to facilitate systems-orientated learning ,10. WhilMost research related to SSIs and systems learning in the classroom has focused on the acquisition of content knowledge, and the alignment with learning outcomes, such as understanding scientific concepts, models, and methods of reasoning ,18. FeweThe topical context area for the HCSs used in the current study was focused on the environmental and social impacts that humans have when interacting with coastal ecosystems, whether as a food supply or a source of recreation. Seafood is a food source with the potential to sustainably feed an ever-increasing population, and provide economic benefits, as the recent United Nations Food Systems Summit demonstrated . The rolIn addition to the environmental consequences, marine ecosystem disruptions have aesthetic impacts on beaches, reduce recreational opportunities, and pose economic problems for community members near or within coastal ecosystems . The pubThe purpose of this study was to explore the use of HCSs in food system education contexts, in which students could learn systems-thinking content from a transformative-learning perspective. Three research questions guided the current study: (1) What were the responses provided by participants for each hypothetical case scenario? (2) How did students navigate the hypothetical case scenarios from a systems-thinking perspective? (3) How can the hypothetical case scenario method serve as a transformative-learning tool?The theoretical framework guiding the current study was transformative-learning theory , which econstructive discourse to use the experience of others to assess reasons justifying these assumptions, and making an action decision based on the resulting insight.Transformative learning refers to the process by which we transform our taken-for-granted frames of reference  to make them more inclusive, discriminating, open, emotionally capable of change, and reflective so that they may generate beliefs and opinions that will prove more true or justified to guide action. Transformative learning involves participation in Three elements are central to transformative-learning processes: experience, dialogue, and critical reflection . ExperieWhile transformative-learning theory was conceptualized by Mezirow (1991) as an eleven-stage process, Boyer et al.  condenseTransformative learning has previously been implemented in relation to food systems and agricultural content see ,40); how; how40])A key component of enacting transformative learning is to engage students in continual high-level reflection, in which they step back and assess what is occurring in the learning situation ,41,42. HA mixed-method research design was operationalized to address the research purpose and questions in the current study. The researchers selected an embedded mixed-methods approach, in which they first distributed a quantitative survey instrument with identical systems-thinking-based HCSs related to the food system, followed by focus-group sessions to debrief with students . A mixedA quantitative survey instrument was distributed to participants through the Qualtrics online survey platform. The quantitative questionnaire contained three HCSs, a Likert-type systems-thinking scale , a greenIn each HCS, the participant was presented with a primary scenario, and asked to choose between two options to address the scenario described. Each participant made their primary choice, then they were directed to one of two possible branched primary outcomes. The two primary outcomes provided a description of the events that took place because of the primary choice, and subsequently presented them with two secondary choices. Once the participant selected a secondary choice, they received a description of their final scenario outcome. Because two sets of secondary outcomes were available per primary outcome, there were a total of four possible final scenario outcomes for each HCS. A graphical representation of the learner process is presented in The three scenarios were presented to individual participants in a random order within the survey instrument, to reduce potential bias, and to mitigate the potential influence of one scenario on another throughout the survey process.The first HCS presented a case detailing select issues surrounding Atlantic cod decline and its effect on coastal communities, drawing upon details from real-life cases of this issue ,51,52. RBefore the survey distribution, a panel of five experts with professional and academic experience in natural resources, aquaculture, agricultural communication, agricultural leadership, agricultural education, extension education, and quantitative methods reviewed the instrument for face and content validity. The focus-group protocol (detailed below) was reviewed for both face and content validity by three university faculty members with expertise in agricultural communication, agricultural leadership, and program evaluation. A pilot test was conducted with a group of graduate students in the University of Georgia agricultural communication course, for both the quantitative and qualitative instruments. Researchers adjusted the protocol according to feedback from both the experts and the graduate students.Researchers developed a focus-group protocol to provide participants with the chance to reflect upon, and deliberate with peers, the various outcomes of each scenario they encountered in the quantitative HCS instrument. Questions within the focus-group protocol were each associated with one HCS contained within the quantitative HCS instrument. A moderator provided a brief definition of the systems-thinking archetype that participants saw in the HCS instrument, before beginning the discussion of each individual scenario. The moderator asked participants to raise their hands to indicate the final outcome they received as a result of their selections in the scenario at hand. Participants were subsequently asked to describe how they went about making their decisions within the HCS. Once participants had the opportunity to discuss this question with their peers, the moderator distributed a physical copy of the scenarios to show participants the different possibilities available as primary and secondary outcomes. One minute after receiving the handout, the participants were asked: (1) what they expected to happen, (2) how those expectations differed from what played out in the scenario, and (3) now that they have seen the whole scenario, would they make different choices. This process was repeated for each scenario. After all scenarios were discussed, the moderator asked participants to reflect upon and summarize in one sentence their perception of the experience with the quantitative HCS instrument, and the focus-group session. To ensure that each participant had an opportunity to respond to this question, the moderator called each participant by name, to provide a turn for their response.Data were collected from 10 November 2021 to 20 April 2022, amongst students enrolled in five courses in the College of Agricultural and Environmental Sciences. The students were advised as to the study’s voluntary nature, and that declining participation would have no effect on their class grade or standing; students voluntarily signed consent forms to participate. Data collection was completed during regularly scheduled class times; however, the primary instructor was not present. All data were collected by the research team, none of whom had existing relationships with participants. A total of 68 students completed both the survey and focus-group portions of the study. Participation was limited to only those individuals who were in class during the data-collection process. All participants elected to participate in the study. The current study was approved and deemed exempt by the University of Georgia Institutional Review Board (Protocol #00004479).When participants arrived in the classroom, researchers asked participants to sign in using an identification number sheet. Participants were then randomly assigned into focus groups, with the goal of 8 to 10 participants per group. First, researchers presented a short overview of what the focus-group sessions would entail, and then they provided participants with a sheet of paper that contained a unique identification number, to ensure participant anonymity in the survey instrument, a room assignment (if needed), and a section for documenting their results associated with each HCS. The provided sheet was used for students to note their anonymous identification number when completing the survey instrument, and for their personal reference during the focus group. Following the dissemination of the identification sheets, the focus groups followed their moderators into designated rooms to begin their individual sessions. Each focus-group room contained 8 to 10 participants. A total of 12 focus groups were conducted across the recruited classes. Students within each focus-group session were given time to complete the Qualtrics survey instrument, and record any reference information about their results. Following the survey, participants engaged in focus-group sessions, the qualitative portion of the mixed-method study.Designed to understand individual and group experiences and opinions about a specific phenomenon through group discussion, focus groups utilize group interaction to gather data . During The focus-group data were transcribed verbatim and then uploaded to MAXQDA qualitative analysis software for analysis. Researchers used an inductive coding approach, and the constant comparative method outlined by Glaser and Strauss . Two autIn accordance with recommendations within the literature , a subjeThe frequencies for the Atlantic cod scenario, using the “tragedy of the commons” archetype, indicated that a majority of participants prioritized sustainability (n = 54) over fishing for food (n = 14) at the first choice stage. Based on the four potential outcomes in the secondary choice stage, most participants (n = 39) selected lobbying for governmental credit systems as their preferred intervention within the HCS see .The second scenario focused on oyster farming, and used the “fixes that backfire” archetype. This scenario illuminated participants’ decisions related to moving to a new location, or expanding in the same location, an oyster-farming operation facing environmental and economic impacts. Initially, most participants (n = 47) chose to move their operation and face potential economic costs, in order to prioritize the environment. At the second choice stage, most participants decided to prioritize their product quality by purchasing expensive land primed for oyster farming (n = 43), considering both the long- and short-term economic impacts of their decision see .The last scenario highlighted a local community commission, and used the “accidental adversaries” archetype see , presentResearch questions two and three were qualitative in nature. Five themes were identified related to systems thinking in participants’ responses: (1) methods for reasoning through scenarios, (2) surprise and frustration at outcomes, (3) understanding of, and confidence in, choices, (4) evaluating systems-level consequences, and (5) thinking through systems complexity.Students used various methods to reason through the scenarios, one being thinking in long-term rather than short-term mental frameworks. For example, one student in focus group (FG) 9 explained their reasoning for the “tragedy of the commons” scenario:I chose prioritizing sustainability because in the long run that would last longer than prioritizing feeding the population. If you fed them all too much at once then you could run out quicker. But if you did sustainability, it could last a little bit longer.Another student explained, “compared to the other [choices], that’s probably the better choice maybe even though you would take the upfront like relocation cost, I think it would pay off in the long run and you wouldn’t hurt the local environment” (FG5). Other students made decisions based on the appropriateness of the solution for the audience: “I […] went the fishing limit route [for the “tragedy of the commons” scenario], because not all of these fishermen are going to have social media to view the campaign that they’re trying to get advice” (FG11). Another student reflected on the appropriateness of the decision for stakeholders, saying:[When] choosing between social media or government intervention, everyone doesn’t have social media. Social media is just [for] a certain generation, or everyone is on different social media sites [….] I feel like it would be hard to reach people with a social media campaign over the government.(FG8)Finally, several students described their decision-making process as trying to minimize negative outcomes within each HCS. For the “accidental adversaries” scenario, one student in FG5 said, “I expected there to be more traffic with the environment. I know it would cause a little bit damage maybe not as much as it as is explained here”.Participating students also expressed surprise and frustration at the outcomes of the scenarios. Several students expressed surprise at there being no correct, or “winning” (FG2), option. Moving through the scenarios, students realized that “every scenario has its downside—that’s what surprised me” (FG2). Other students were frustrated with this non-linearity, saying, “ all the choices make someone angry and you always lose your campaign, there’s no win here” (FG5). Some students experienced unmet expectations in their decision-making:I [would] still choose what I chose, but I’m sad when you know what happened. I made those decisions. I thought that sustainability will always work through and it’s not just planning ahead, because it will work out, but it doesn’t work out.(FG11)Other students stated that, knowing what they knew now about the results, they would change their choice: “Knowing all of the answers now, I’d rather have a nice environment than to have another [touristy] beach somewhere, so that’s what I would’ve done” (FG10). The scenarios provided reflective opportunities to discuss unintended consequences from decisions after the systems-thinking debrief. One student reflected:When I prioritized environmental sustainability, I thought that it was going to be the right choice, or it was going to have a good ending. But [… my results] just showed me how […] things that you won’t plan for also go wrong. [In the fixes that backfire scenario…] it’s more than that, it’s consider[ing more] than just a typical, one size fits all type situation to cover up the issue of at hand.(FG9)Within the third theme, understanding of, and confidence in, choices, participants had various reactions to navigating the decision-making process, leading to different learning outcomes about their own ways of thinking. Two subthemes were identified, which categorized participant responses: justification of choice, and comparing outcomes. Participating students provided several examples of the justification of their choices. Related to the oyster-farming scenario, a participant outlined their decision process:I chose to remain in the same location on that first choice because the conservation green lighted it. I figured I’d go ahead and try it and until something new arose instead of trying to preemptively change my mind. Then when something did arise, I chose to go ahead and cut back on those detrimental actions to preserve the environment. I had pretty good outcomes with [that choice].(FG11)Another student explained, related to the “tragedy of the commons” scenario, “I was evaluating the other option, but I would still stick to sustainability […] just because social media doesn’t really resonate with me” (FG2). Other students were confident in their choices, and justified their decision through comparing the various outcomes. A student in FG8 stated:I would stick on that path. I [figured] I would face more cost in the beginning, but that’s a risk that you have to take in a business anyway, and then making those more expensive choices set me up for success in the long run to pay it back and then profit off it.Participating students engaged in different techniques to evaluate systems-level consequences, the first being comparing hypothetical with real-world challenges. One student explained, “we thought we had unlimited money […] So in a mythical world, yes, I would relocate, but in the real world who knows what would’ve been my best option in terms of finances and everything” (FG10). Other students evaluated tradeoffs between economic prosperity and environmental sustainability: “it’s difficult to realize both environmentally sustainable fishing practices and doing beneficial business” (FG10). Another way in which students explored systems-level consequences was through evaluating the various risks associated with each option in the HCSs. A student explained their reasoning through the decision-making process:I  I’m going to just take the risk of relocating. When it came to the other options, I’d much rather pick high quality over something lower […] So I just want what’s best and then I’m going to assume the consequences of my actions […] It’s just a risk of getting to a higher level, there’s always going to be a risk.(FG2)Overall, participants chose to prioritize sustainability, economics, or the community in their decision-making process. Some students relied on their backgrounds and previous experiences to make their choice:I came from a really small town. The people that ran for office were people who grew up there. They wanted the best for the community. I lost reelection but it doesn’t bother me because I did what I thought was best for the community. (FG6)Other students prioritized sustainability, stating “I opted for the environmentally safe one” (FG6), “I tried to keep sustainability in mind when making those choices” (FG7), and “I wish I had chosen to focus on sustainability […] since the environment’s damage was permanent” (FG4). Evidence of participants prioritizing economics included statements such as “I was just thinking in terms of money” (FG7), “I chose to purchase more expensive land. I kind of figured obviously lose profit, but if you purchase more expensive land and just work harder, you’ll make your money back” (FG2), and “I’d rather have top quality oysters and sell them, make a profit on those instead of giving lower quality oysters, which my business can again suffer” (FG6).Finally, the fifth theme was thinking through systems complexity, where students imagined improvements to the scenarios, complexified potential solutions, and recognized the unintended consequences of decisions. Recognizing the inherent limitations of only having four choices, participating students dialogued about what they would change to make their result more suitable for a variety of stakeholders:I feel like something […] that might be interesting is if we wind up with result [increasing investments to local conservation efforts ], there’(FG11)Another student explored a third possibility not presented in the scenarios: “Out of those two choices, there could’ve been a third choice that might’ve been a better option, like placing a temporary ban on the Atlantic cod or just making it a little harder to fish [through other] regulations” (FG1).Related to unintended consequences, one student reflected, “in the end, everything will have a downside. Whatever decision we make, so you just want to do good, do what’s best, what you think is best” (FG2). Another student mused, “I realize that sometimes a good heart and good intentions, don’t always have positive consequences, and [that] made you realize how many unintended consequences were coming from every action that we ‘chose’” (FG9). A student reflected, “most decisions often have unpredictable outcomes” (FG3).Four themes were identified to provide evidence for using HCSs in a transformative-learning context: using previous knowledge and experience, experiencing difficulties and confusion, developing new ways of thinking, and experiencing positive learning outcomes. Several students described how they used their previous experiences and existing knowledge to help them chose an option in the HCS. One student explained,I think [my choice] has to do with the fact that I grew up in Las Vegas. I was immersed into tourism culture. In my head it didn’t bring benefit. I saw a lot of the bad parts of it. So, I just figured community-based [industry] might be better.(FG6)Other students experienced difficulties and confusion in the decision-making process, emulating a disorientating dilemma. Often, the disorientation came from pedagogical strategies that were new to students: “I feel just because we are in school I expect there to be a ‘right’ answer, so sometimes it’s a little frustrating because you’re trying to get to the right answer and everything’s wrong” (FG7).Other participating students described how the HCSs helped them to develop new ways of thinking, or to think about their cognitive processes in a different manner. Many reflections came from the perceived differences between the real world and what is learned in the classroom: “[this activity] was very helpful to see that, our actions could have drastic consequences. There’s rarely a right or correct answer when it comes to our choices in life outside of a classroom” (FG6). Another student explained what they learned about deficits in their own thinking: “I learned I did not realize the trickle-down effect of potential choices” (FG10).Overall, participating students felt the HCS activity had positive educational outcomes. When asked to describe the HCS experience, one student stated, “I feel like it was educational and I really like how this study is discussion-based because you’re able to see other people’s choices and how their backgrounds can affect their choice-making” (FG6). Another student described the activity as “very thought-provoking and informative” (FG3). The discussion-based setting of the HCS activity was a key component appreciated by participating students:I think it was interesting just to get to hear everyone’s perspective and like opinions, because I think it really emphasizes on the fact that your opinions are built [out] of where you come from, who your family is, where you live, and [your] background. So I thought that was interesting to hear about and just to see everyone’s perspective.(FG2)Overall, the results indicated that the HCS activity was an impactful learning tool for increasing students’ capacity to engage in systems thinking around SSIs, particularly related to food-system scenarios. Participants in all 12 focus groups were highly involved in the discussions and debriefs of the HCSs, leading to generative dialogue and exposure to others’ perspectives and experiences. For many students, the HCSs were also their first time exposed to educational content around seafood and costal industries. The HCSs may then serve as an engaging strategy for introducing new, complex scientific and food-system topics into the classroom, especially those related to the SDGs.The quantitative analysis of the HCS choices revealed that higher numbers of participants were likely to choose environmental sustainability, as exhibited by the popularity of the first choices leaning toward environmental sustainability in both the Atlantic cod scenario (“tragedy of the commons”) and the oyster-farming scenario (“fixes that backfire”). In the “accidental adversaries” scenario, participants were more evenly split between the tourism and fishing industries, neither of which were inherently environmentally sustainable. However, the qualitative analysis of the focus-group reflections emphasized the complexity of students’ decision-making processes, and allowed them to exhibit knowledge of complex topics beyond that of environmental sustainability, even when the content area was unfamiliar to many participants.Participating students exemplified components of systems thinking in their decision making, specifically evaluating tradeoffs between the three legs of sustainability  , as wellDespite positive results, there are limitations associated with the current study, which should be acknowledged. Firstly, due to the authors’ need to use an educational setting as an intervention, they relied on convenience samples of students enrolled in courses within the college of agriculture to recruit participants. Thus, findings are exploratory, and should not be generalized beyond the sample. Additionally, participants may not have been a representative sample, due to the non-random sampling techniques used; however, the participant demographics were provided, to enhance the transparency of the sample. An additional limitation was that the HCSs were implemented as a one-time intervention in each of the five classes in which participants were enrolled, and thus limited to a single point in time, as opposed to an ongoing learning approach used throughout the duration of the course. However, the results from the single intervention suggest that HCSs have the potential to foster systems thinking, especially from a transformative perspective, by introducing a disorienting dilemma, encouraging dialogue, and constructing reflection about metacognition. A recommendation would be for future studies to examine the use of HCSs to explore students’ systems thinking and transformative learning over a longer duration, replicating not only the HCSs presented here, but also adapting HCSs to other food-system topics. The measures of impact could incorporate both quantitative scales to measure systems-thinking capacity, and reflection and group dialogue. Another consideration is that, despite the HCSs and systems thinking being interdisciplinary in nature, the majority of participants came from majors defined as disciplinary. Thus, participating students may not have been introduced to interdisciplinary work, such as systems thinking, prior to the educational intervention. Alternatively, there was not a measure of participants’ previous exposure to interdisciplinary work at the undergraduate level. Future research should explore how the role of interdisciplinarity in participants’ backgrounds could impact their experience of the HCS intervention. Finally, class periods were limited to 45 to 60 min, which limited the focus-group debrief and dialogue that occurred. The implementation of the full HCS process is recommended to be a minimum of one hour and a half, to account for set up, the HCS activity, and debrief, to ensure that all students have the opportunity to fully participate.Building from Mezirow  and BoyeThe process initiates with a student as an individual, able to build upon and reconstruct their preconceived notions of a topic. The second stage contains the disorientating dilemma; in this case, the HCSs as a learning tool to introduce cognitive dissonance between the student’s preconceived notions and the unintended outcomes of a systems perspective for problem solving. After the student experiences the disorientating dilemma, the instructor facilitates learning and concept reconstruction, by introducing systems-thinking concepts related to the HCS learning tool. This stage acts as a debrief and foundation for student reflection on the HCSs themselves. The fourth stage contains collaborative reflection, which occurs during the debrief, between the individual and the group. This stage allows for the collective reconstruction of assumptions and concepts related to the HCSs. Finally, the cycle terminates, and reinitiates back at the first stage, where the student integrates the new reconstruction of the concept, and connects to other related notions within and beyond the process.HCSs, as a transformative teaching tool, have the potential to leverage SSI education, specifically relating to complex issues, including those related to food systems. Now, and into the foreseeable future, science and food educators have a responsibility to contribute to a sustainable future. Through educational strategies such as HCSs, educators can help students to contextualize human actions as being integrated within the environment, and to better understand how their actions and decisions can have impacts well beyond the proximal cause and effect observed within a finite situation . Future


Numerous chemical probes have been used to measure or image oxidative, nitrosative and related stress induced by free radicals in biology and biochemistry. In many instances, the chemical pathways involved are reasonably well understood. However, the rate constants for key reactions involved are often not yet characterized, and thus it is difficult to ensure the measurements reflect the flux of oxidant/radical species and are not influenced by competing factors. Key questions frequently unanswered are whether the reagents are used under ‘saturating’ conditions, how specific probes are for particular radicals or oxidants and the extent of the involvement of competing reactions . The commonest-used probe for ‘reactive oxygen species’ in biology actually generates superoxide radicals in producing the measured product in aerobic systems. This review emphasizes the need to understand reaction pathways and in particular to quantify the kinetic parameters of key reactions, as well as measure the intracellular levels and localization of probes, if such reagents are to be used with confidence. While most papers in this Special Issue focus on modified endogenous biological molecules as markers of oxidative, nitrosative or other changes initiated by free radicals, such damage has also been routinely assessed using exogenous, xenobiotic molecular probes. Thus, as described below, a reduced fluorescein dye has been widely used to detect the production of  ‘reactive oxygen species’ in biological material or biomolecular models—astonishingly, in over 6000 studies to date—despite the obvious shortcomings discussed below. Hence, it is important not to take a too narrow or literal viewpoint in considering ‘biomarkers’ of oxidative stress and radical damage.and rate constant for all the competing reactions. Hence, whether damage is assessed by endogenous biomarkers or by added chemical probes, chemical kinetics is central to an informed assessment of the damage pathways, and the availability of rate constants for specific reactions involving free radicals (in particular) and potential biomolecular targets (or reasonable models for them) is central to an informed discussion about competing pathways in free-radical biology. Of course, the intracellular concentrations of reactants or probes are equally important, and cellular heterogeneity is a daunting challenge to the accurate chemical modelling of biological pathways, as discussed elsewhere in the context of radiation damage ) for •OH radicals in mammalian cells has been estimated as ~8 × 108 s−1, compared with the corresponding value for •OH reacting with 0.3 mM DCFH2, i.e., ~4 × 106 s−1; so, clearly it is most unlikely that DCFH2  can intercept a significant fraction of •OH radicals.Considering, as an example, competing reactions between COat pH ~7 , i.e., ~does GSH .) Nominaectively , i.e., bKinetic competition may also be exhibited between the activated peroxidase intermediate (such as HRP Compound I) reacting with either the probe or endogenous antioxidants; so, for a full understanding of probe chemistry, quite extensive studies must be undertaken. These are likely to involve several sophisticated techniques; in this case, electron paramagnetic resonance spectroscopy to identify reaction intermediates, stopped-flow rapid mixing to measure the rates of non-radical reactions, flash photolysis to monitor reactions of excited states (see below), high-performance liquid chromatography to measure intracellular uptake, preferably in specific organelles, and  pulse radiolysis to generate specific ‘ROS’ in known amounts and monitor their reactions in real time.both the rate constants of the reactions of putative reactants with a probe and the estimates of the intracellular  concentrations of the probe, it is obvious that users are working in the dark in seeking to quantify reactive oxidants using such probes. Actually, users had best work in the dark, because a further complication is that visible light can generate an excited state of DCF, quenched by cellular reductants such as GSH or NADH (and doubtless other reactants such as ascorbate) to generate DCFH• and hence O2•− [® Red has also been reported, once again involving the production of superoxide radicals [Even leaving aside the obvious contraindication of the generation of one specific ‘ROS’  via the obligate involvement of an oxygen-reactive radical in the formation of the fluorescent product, without measurements of nce O2•− . Photooxradicals .2 is not the only ‘ROS’ probe to be a ‘self-fulfilling prophesy’. As discussed in more detail previously [N-methyl acridinium salt, lucigenin , is reduced to a radical LC•+, probably by flavoprotein reductases, and exhibits chemiluminescence on reaction of this radical intermediate with superoxide radicals via an unstable intermediate producing an excited state of N-methylacridone [•+ reacts with oxygen to generate superoxide [6 M−1 s−1:2+/LC•+ couple is –0.28 V vs. NHE, the equilibrium constant of the reaction is ~50; the reverse reaction producing LC•+ from superoxide must have a rate constant of ~6 × 104 M−1 s−1 and is unlikely to compete with the reaction of O2•− with superoxide dismutase in experiments involving loading LC2+ into mammalian cells [DCFHeviously , the bisin LC2+, , 2, is racridone . Howeverperoxide ,116 withan cells . Again, an cells .have exhibited a clear understanding of the problems; the collaboration between the Institute of Applied Radiation Chemistry at Łodz University of Technology and the Medical College of Wisconsin has been particularly fruitful  has a 27-page chapter devoted to ‘Probes for Reactive Oxygen Species, Including Nitric Oxide’, the terms ‘rate’ or ‘rate constant’ are both conspicuously absent.Even if repeated warnings about the shortcomings of commonly used probes continue to be ignored, some groups l , which superficially is similar to that of lucigenin in that the oxidized probe reacts with superoxide to form a detectable product. The oxidation of hydroethidine by O2•− has a rate constant around 2 × 106 M−1 s−1; the rate constant for the reaction of (HE)•+ with O2•− to form the measured product, 2-hydroxyethidium, is orders of magnitude higher; so, the first reaction may be rate-limiting, depending on the concentrations of HE and (HE)•+—at least in systems where only O2•− is the oxidant: obviously, other oxidants can achieve the first step, as directly observed using radiolytically produced radicals [In particular, the generation of specific radicals by pulse radiolysis was used to estimate key rate constants involved in the detection of superoxide radicals by dihydroethidium , has been quite widely used to assay hydrogen peroxide, peroxidase-catalyzed oxidation yielding the fluorescent dye resorufin. However, other oxidants, including biological oxidants, are also reactive: stopped-flow kinetic spectrophotometry was used to demonstrate that peroxynitrite-derived oxidants, but not peroxynitrite, also oxidized the probe, and pulse radiolysis quantified the reactivity towards carbonate radicals, although at pH 10.3 . Interm5), was also characterized using pulse radiolysis, with a rate constant for the reaction of the probe with O2•− of ~1.4 × 107 M−1 s−1 measured [The reactivity towards superoxide of a new mitochondria-targeted probe, the phenanthridine derivative ‘MitoNeoD’ , 5, was measured . The det•OH and H• [2•/O2•− [3•−, •NO2 and ClO2• [https://kinetics.nist.gov/solution/, accessed on 23 May 2023), it too suffers from not being updated and has strict syntax. It should be noted that PubMed will often miss relevant studies of a purely chemical nature. The majority of the rate constants involving reactions of interest involving free radicals have been obtained using radiation–chemical methods, and the inclusion of the term ‘pulse radiolysis’ as a search term may help filter literature searches for relevant kinetic data in both PubMed and Chemical Abstracts (SciFinder®). However, in recent years several pulse radiolysis facilities in Europe have closed down, and this is a barrier to the future application of the technique in this area.While there are very few rate constants measured for reactions of radicals with the specific chemical probes of the general type discussed here, there are useful, if dated, compilations of expertly evaluated rate constants for reactions of H and H• ,124, HO2[2•/O2•− , peroxyl[2•/O2•− , inorgannd ClO2• , phenoxynd ClO2•  and alipnd ClO2• . It may Biochemists familiar with enzyme-catalyzed reactions will take for granted that an assay for an enzyme will involve conditions such that the catalyst is rate-limiting, rather than the concentration of the substrate(s) : saturating conditions characterized by Michaelis–Menten kinetics. Yet, in attempting to assay ‘ROS’ and other biological oxidants, the necessary parameters to evaluate whether a probe is used under saturating conditions or to estimate the fraction of the oxidant that is being detected—the products of rate constants and concentrations for reactions of both probe and competing reactants—have often been ignored or are simply not available.before using a probe, based on earlier discussion [Where is the probe located, and what is its concentration? Consider, if appropriate, whether there are likely to be extracellular–intracellular concentration gradients or inter-organelle or other local variations in the concentration of the probe . Measure, or at least estimate, the probe concentration(s) in the region(s) of interest.What are the species likely to react with the probe? Consider all the putative species being generated and their reactivities towards the probe, as estimated by the product of rate constant and concentration, preferably under relevant conditions .What are the reaction pathways involved in the generation of the final product being measured? Identify reaction intermediates if possible, noting that spin conservation is likely to dictate the obligate formation of intermediate free radicals from radical oxidants.Is a catalyst involved in the reaction(s)? Consider whether the concentration of the catalyst may be rate-limiting and whether the presence of the catalyst results from the treatment being assessed, e.g., the release of cytochrome c from mitochondria as a result of apoptosis initiated by the oxidative challenge.What are possible competing reactions, firstly involving kinetic competition between the probe and cellular antioxidants for the species of interest ? The Law of Mass Action will dictate the extent of the competition involving reactions of the species being assessed with endogenous reactants, especially with antioxidants: thiols, ascorbate, urate, NADH, α-tocopherol, etc., and other redox-active reagents .Do the intermediates in probe chemistry react with endogenous molecules in competition with pathways leading to the final, measured product? Again, the Law of Mass Action is central to an analysis, and quantifying the redox properties of reactive intermediates will help suggest possible reactants. The archetypical example is the reaction with oxygen of the obligate intermediate radical obtained on oxidation of reduced fluorescein dyes—oxidation either by radical species or by intermediates formed in the catalyzed reaction with hydrogen peroxide—to generate superoxide radicals.Are there any potential effects of the cell culture medium (if used)? Consider comparing the results in full medium  with those from cells suspended/plated in as pure phosphate-buffered saline as can be obtained.Could there be artefacts arising from the photochemical properties of the probes and products? Visible light  may initiate photochemical reactions; photochemically induced excited states may be much more reactive towards cellular reductants than the probes themselves. Consider whether the product build-up is sufficient to initiate inner-filter effects by absorbing a significant fraction of the incident light, e.g., in fluorescence plate readers.How far is the measured product likely to diffuse from the site of interest or ‘leak’ from cells? This will be time-dependent and, within a specific organelle, can be estimated from the likely diffusion coefficient and the Einstein–Smoluchowski equation, but trans-membrane transport should also be considered.Does the probe itself affect cellular function? Probe and/or product may bind to macromolecules or change the mitochondrial membrane potential or may initiate apoptosis and lead to potential catalysts released during the experiment .The applications of chemical probes vary widely, and the criteria for using them in cell-free systems may be very different from those for cellular models and especially tissues. However, it may be useful to reiterate briefly the main questions that researchers should ask scussion ,13,30:WhTo design, synthesize and use with confidence a chemical probe for reactants of interest in free-radical biology is a daunting prospect, requiring skills spanning disciplines, and techniques and instrumentation unlikely to be found in a single laboratory. The chemical obstacles to the use of the commonest probe for ‘ROS’ have been discussed previously (and repeatedly) but were summarized here with emphasis on kinetic factors, as a pointer to some of the properties which must be considered in the rational use of probes.almost guarantees a vague output in the use of the probes. As a group of experts recently noted [Some readers may find the discussion above of the language of free-radical biology and the advice to avoid the term ‘ROS’ wherever possible to be unrealistic, pedantic and repetitive. Yet, in the view of the present author, the language is a major part of the problem. The term ‘reactive oxygen species’ may have arisen in the early days of free-radical biology, when the emphasis was on Fenton chemistry and the term simply avoided distinguishing between free hydroxyl radicals as a product of iron/hydrogen peroxide chemistry, or whether an iron-oxo species was the reactant. The index to the second (1989) edition of a standard text discussing free radicals in biology and medicine does not include ‘reactive oxygen’ or ‘ROS’ . Now, thly noted , ‘Multipdo have a clear grasp of the problems to be addressed. Kinetic measurements in which specific chemical entities are generated and their reactions followed directly to quantify reactivity are central to the successful application of chemical probes for oxidants and radicals in biology, but the rate constants are only part of the story; the local concentrations of the probe and possible endogenous reactants at specific sites in the cell are equally important. It is hoped the list above of questions that users should first consider in the use of chemical probes may, at the very least, help scientists to be aware of the uncertainties which arise if these factors are ignored.In the present article, the author has again stressed the pitfalls in the use of the commonest probe for ‘ROS’ to illustrate what can go wrong if a careful study of the literature is outweighed by the convenience of purchasing and using a commercial reagent where the manufacturer has glossed over the problems. This was followed by a brief mention of some recent studies which show that leading workers in the field


The following study employed an instrumental case study to investigate sport stakeholders’ understandings of behavioural management strategies used in competitive youth baseball, including the identification of common strategies and interpretations of these as punishment or discipline. Twenty-one participants, from one competitive (AAA) all-boys baseball team, including three coaches, eleven baseball players, and seven parents, were recruited to participate in an individual semi-structured interview. Interviews ranged between 30 and 150 min, and data were analyzed using reflexive thematic analysis. Several behaviour management tactics were identified, of which exercise, benching and yelling negative comments were most often reported. While participants interpreted excessive exercise and benching as punitive and/or disciplinary approaches to behavioural management, yelling was consistently viewed as punitive. Participants confused punishment and discipline as interchangeable, thus suggesting a lack of awareness regarding developmentally appropriate strategies of behavioural management and highlighting the normalization of certain punitive tactics in youth sport. The results underscore the necessity of imparting knowledge to the sports community regarding age-appropriate behavioural management interventions to foster safe and enjoyable athletic experiences for youth competitors. When designed and delivered in a developmentally appropriate manner, participation in organized sport has been linked with positive physical and psychosocial outcomes for youth ,2. InforPunishment is defined as the application or withdrawal of a stimulus by an authority figure in response to perceived wrongful behaviour, which is meant to decrease the likelihood of that behaviour being repeated . PunishmInformed by the detrimental effects of punishment, a shift from using punitive practices to developmentally appropriate disciplinary strategies has occurred in parenting and education ,14,15. DDespite the adoption of more positive disciplinary approaches in other child-populated domains, research on behaviour management in sport suggests that punishment continues to be used to modify athlete behaviour. For example, researchers have examined common forms of punishment used in sport, such as excessive exercise , yelling, and benching  as consequences of perceived undesirable behaviour  ,20,21,22In response to documented negative repercussions of punishment use, researchers, sport leaders and policymakers have denounced the use of coaching tactics such as excessive exercise and yelling ,25,26, aBased upon the evidence of harms associated with punishment use, and the shift from the use of punitive to disciplinary strategies in other youth-populated domains, a question is raised about why punishment continues to be used in sport contexts. While researchers have examined the perceived reasons for use and effects of behavioural management tactics in youth sport ,20,30, tThe current research employed an instrumental case study approach to investigate the conceptualizations of behaviour management among athletes, coaches, and parents of a competitive youth baseball team at the AAA level . The goaThe current study is situated within a constructivist paradigm, which permits us, as researchers, to critically discuss and reflect on varying conceptions of behaviour management in sport with our participants ,34. ConsThe case of interest was a competitive all-boys baseball team from a large city in Canada. According to the league the team was affiliated with, the team is classified as a 14U Triple A (AAA) youth baseball team, which is considered one of the highest levels of competition for baseball participants within this age group. There were twelve boys affiliated with the team, three male coaches, and twenty-two parents/caregivers. The season was eighteen weeks long and consisted of three preseason games, thirty in-season games (fifteen home games and fifteen away games), three local tournaments, and one international tournament. Collectively, the boys practiced between two and three times per week. The team was affiliated with an organization that the parents described as notorious for selecting “intense and unorthodox coaches”. The principal investigator, who coached and umpired in this league, had witnessed firsthand the wrath of such coaches . To be included in this study, participants had to be affiliated with this team in the capacity of an athlete, coach, or parent/caregiver.Case studies are typically described as being specific and bounded in place and time . Thus, pCase study research is less concerned about answering questions of ‘how much’ or ‘how many’ but rather focuses on answering questions of ‘how’ and ‘why’ . As suchEthical approval for this study was obtained from the University Research Ethics Board . Coaches and parents were asked to provide written consent prior to participating, whereas athletes were required to provide written assent, given they were under the age of consent . Additionally, written consent from the parents was elicited to confirm they approved of their child’s participation in the study. To maintain participant confidentiality, a pseudonym was assigned to each participant, and all personal identifiers were removed. Youth athletes’ perspectives were sought given previous research which has suggested punitive strategies may have a detrimental impact on developmental outcomes  ,20. FurtConsistent with the constructivist paradigmatic position upheld for the research, participants were invited to share their perceptions of behaviour management strategies used in youth sport and asked to describe whether they perceived these strategies as punishment or discipline. One individual, face-to-face, semi-structured interview was conducted with each participant. The length of the interview varied across the three participant samples; athlete interviews ranged between 30 and 65 min, parent interviews ranged between 70 and 110 min, and coach interviews ranged between 90 and 150 min. The principal investigator conducted all interviews, which were transcribed verbatim and, with the permission of the participants, were audio-recorded.The interviews began with broad, open-ended introductory questions, pertaining to behaviour management. For example, coaches and parents were asked questions, such as “What are common tactics used to manage athlete and/or team behaviours on your team?” Similarly, athletes were asked, “What happens when you or your teammates do something wrong, such as arrive late to practices/games, not pay attention, or disrespect others?” After the participants’ descriptions of the common methods used, all participants were asked whether they understood these methods as punishment or discipline and probed to explain why. Probes were intentionally used to clarify participants’ responses and to gain a more comprehensive understanding of participants’ interpretations of behaviour management strategies used in youth sport. The findings contained in the current study focus specifically on participants’ interpretations of behaviour management strategies used in youth sport as forms of punishment or discipline.Interview transcripts were analyzed using a reflexive thematic analysis (TA), characterized as an open and recursive process used to provide clear and convincing interpretations of the data . The refA collaborative approach to data analysis was adopted for the current study. For example, following interview transcription, the principal investigator engaged in member reflections with participants; this was to ensure the passage of time did not negatively impact the participants’ ability to recall information discussed throughout the interview. Member reflections facilitated critical dialogues, which led to a better understanding of participants’ views, the generation of new insights, clarification of thematic interpretations, and the development of new supporting evidence . For exaFurther, the co-authors, who served in the capacities of a supervisor and colleague, operated as critical friends throughout the data analysis process. Specifically, research team members routinely engaged in collaborative discussions throughout the data analysis process to reflect on and discuss emerging themes and to ensure the participants’ views and main messages of the data were adequately represented . These dThe purpose of this study was to investigate sport stakeholders’ understandings of behaviour management strategies used in youth sport, including the identification of commonly used strategies and interpretation of these strategies as discipline and/or punishment. Participant responses revealed that exercise, benching, and yelling negative comments were the most common behaviour management strategies used with this youth sport team. Participants struggled to differentiate exercise and benching as punitive or disciplinary in nature but consistently interpreted yelling negative comments as punitive. The responses presented are not unique to each athlete, parent, and coach but represent overarching interpretations and common meanings identified throughout all participants’ responses.The participants identified exercise, benching, and yelling as the most common behavioural management strategy used by coaches. Some participants referred to setting up the field, cleaning up equipment after practices and games, and in extreme situations, asking an athlete to stay home as additional strategies to manage athlete and team behaviour.All participants referred to the use of exercise  as a method of correcting athlete behaviour perceived as undesirable or problematic. Mina (athlete) shared, “It’s not uncommon for us to run after a bad loss or practice”. Patrick (assistant coach) attested to the use of exercise in response to poor performance, as he stated, “if they [team] don’t want to work hard when it counts, then they’re going to stay back and work hard after. Usually, a few wind sprints reminds them to come to the field ready to work”. Exercise was also frequently used to address behaviours perceived as disrespectful. For example, Laura (parent) explained, “kids would run laps if they were disrespectful. Swearing at a coach, a player, an umpire…if there’s disrespect, then there’s going to be kids running laps…they’re going to feel some pain…they’d run until they’re exhausted”.Many participants identified benching as a behaviour management strategy that coaches used to manage individual athlete behaviours. For example, Derrick (assistant coach) admitted, “We [coaches] bench players based on their performance. I’d be the first to say, ‘bench my son’ if he’s playing like crap”. Diego (athlete) agreed that benching was used as a response to individual poor performance: “We’re playing high level baseball. If you’re not playing good, you’re sitting. That’s only fair. It’s not great, but you can only play nine guys. The nine best should play, while the others sit until they prove otherwise”. Similar to exercise, participants indicated benching could be used in response to other undesirable behaviours, such as arriving late to practices or games. Phil (parent) stated, “Showing up late to practice or worse, a game, means you don’t care. So, sit on the bench. If you don’t care about your team or coaches enough to show up on time, then sit out”.The participants recognized yelling negative comments as a form of behaviour management used by coaches when they were extremely upset. For example, Eric (athlete) shared, “…we played like absolute shit, I think we lost by 8 or 9, and [coach] laid it on us…he told us we’re wasting his time. He said we’re so bad that we’d strike out playing t-ball”. Alyssa (parent) explained that coaches would yell in response to aggressive behaviours such as fighting: “The coaches expect the boys to respect one another. When they start fighting, either physically or verbally, you can expect the coaches to yell. I know that type of behaviour makes them so mad”. Finally, Patrick (assistant coach) admitted, “if they [athletes] give me lip, they’re going to get it back tenfold. I’m not volunteering my time to be disrespected”.Although not as frequently referred to, the participants identified alternative behaviour management strategies in addition to exercise, benching and yelling. Following a bad game, Jim (head coach) revealed he has asked the athletes to set up the field and clean up the equipment:I like to get to practice early to clear the tarps and rake the infield. Sometimes I even give the grass a quick cut. It would take me about an hour to do everything, then we practice for two hours, and then clean-up for another half hour. If the boys have a bad game, then next practice, they’re on set-up-clean-up duty. On those days, I make sure we cut the grass.In one extreme example, Martin (athlete) admitted he was instructed to stay home from practice for purposefully attempting to injure an opponent during a game. Martin shared, “I was pitching, and I meant to hit the [batter] in the back but I hit his head. Thankfully, he had a helmet. Coach pulled me and told me not to come to next practice”.As previously discussed, the participants cited exercise, benching, and yelling negative comments as the most common behavioural management strategies used on this sport team. When probed about these tactics, many participants struggled to determine if exercise and benching were used punitively or disciplinarily, but there was a consensus amongst the group that yelling negative comments was used punitively.According to the participants, the use of exercise was a common tactic used to manage youth athletes’ behaviours. Many participants understood exercise as a strategy that can be used to punish and discipline athletes whose behaviour was perceived to be disrespectful, unfocused, and lazy. Derrick (assistant coach) explained “exercise as punishment is directly correlated to disrespectful behaviour towards your coaches, teammates, officials. Exercise as discipline is about a lack of effort, being lazy on the field, careless mistakes. These are unacceptable and exercise gets them to refocus”. Eric (athlete) also explained that exercise was a commonly used punishment in response to disrespectful behaviour but suggested that if you learn from the punishment, it then constitutes discipline: “If you are being disrespectful to the coach, then obviously exercise is being used as punishment because you shouldn’t be disrespecting someone who is volunteering their time…if you learn your lesson from the exercise, then it’s discipline”.Laura (parent) shared similar sentiments about exercise being both punishment and discipline: “[Exercise] is punishment because they are being punished for bad behaviour, but it’s discipline because they are learning to take responsibility for their actions…they learn from the pain which teaches them not to screw up again”.Feelings of pain associated with excessive exercise were reportedly necessary for athletes to learn right from wrong through exercise. Val (athlete) explained, “when you feel pain it’s punishment because it’s meant to hurt you. It tells you not to screw up again or else this is what’s going to happen…nobody wants to experience pain”. Additionally, Phil (parent) stated, “it’s gotta hurt at least a little bit. It’s what makes exercise an effective punishment”. In contrast, participants such as Mina (athlete) referred to experiences of pain as an indicator of an effective disciplinary strategy: “Twenty push-ups or five laps every time I screw up, well now it’s going to hurt a bit. That’s when you learn what not to do, so [exercise] would be discipline when it’s painful because we’re learning”.When referring to the use of exercise, the participants also acknowledged the intensity of the activity as a potential factor in distinguishing the experience as punishment or discipline. For example, Tim said, “…punishment is more of you being bad so now you have to do ten laps. Discipline, I feel like, is running four laps instead of ten”. Similarly, Caleb (athlete) stated:If there’s a visible difference, like…doing ten laps and knowing your players can’t do it versus doing one lap and having a conversation with the player about what he did wrong and how he could improve, that’s the difference between punishing and disciplining.Although some athletes perceived ten laps as severe punishment, Patrick (assistant coach) perceived ten laps to be a reasonable form of discipline: “…ten laps isn’t that bad…maybe twenty would be punishment”. When asked to explain the most effective way of managing misbehaviour, Patrick responded, “Run them until it hurts. I don’t think you need to do it all the time, but sometimes I think it helps. Gets them focused and paying attention to us”. Derrick (assistant coach) agreed that running was an effective method of managing behaviour because “it teaches them [athletes] to wake up…that the mistakes they have made are unacceptable and that they are better…a good hard run gets the job done”. Overall, the quotations contained within this section highlight conceptual confusion regarding the use of exercise as a behaviour management strategy, with participants suggesting exercise is used as punishment, discipline, or both.Similar to exercise, benching as a behavioural management strategy was perceived as both a punitive and disciplinary method. However, unlike stakeholders’ perspectives of exercise, views of benching differed between stakeholders with athletes viewing benching as punitive, and adult participants predominantly suggesting it was disciplinary. For example, Diego (athlete) suggested, “[benching] is punishment…not playing someone is the worst thing you can do to an athlete. It’s an extreme punishment”. Likewise, Martin (athlete) stated, “benching is the worst punishment. If I make a mistake and coach sits me, he’s punishing me for not being good enough. It’s a terrible feeling”. Alyssa (parent) agreed that benching is used in response to poor performance; however, she suggested it was a disciplinary tactic:Baseball is a team sport and if they’re not playing well, then they need to sit. Having them out there does no good to them or the team. If a player keeps on making the same mistake, he’s just going to feel bad about himself and feel bad about hurting the team, so you have to sit him…[benching] is purely disciplinary. It teaches kids the importance of sacrifice, putting the team’s needs above your own. These boys aren’t babies. This isn’t t-ball anymore. These are elite boys who can learn a lot from the sidelines.Alyssa’s comment suggests benching may teach values such as sacrifice and selflessness, which can benefit the team, thus making it an appropriate disciplinary strategy to be used at the competitive level of sport. The benefits of benching as a disciplinary strategy were echoed by Derrick (assistant coach), who shared:I use benching as discipline. It’s good…because it’s quick feedback. For me…the best form of feedback…I’m okay with benching. I’m trying to convey expectations through benching, trying to build character and resilience. I want the boys to know they need to work hard and earn their spot on the field…benching isn’t reactive like punishment. It’s a strategic form of discipline.Participants noted that the amount of time on the bench influenced whether they interpreted benching as punishment or discipline, suggesting that benching for a short period of time constituted discipline whereas longer periods of time spent sitting out was punishment. Brian (athlete) clarified:I guess it depends on how many innings you sit. If you make a bad throw to home from right field, discipline would be maybe, sit an inning, reflect on what you did…if you make an error and strike out a bunch of times and bring your team down, maybe sitting the whole game then would be punishment.Erica (parent) agreed that extended periods of time spent on the bench represented punishment: “To punish individuals you can bench them the whole time…make them sit out a whole game”. Similarly, Patrick (assistant coach) stated, “If you sit a kid an entire game, maybe back-to-back games, that’s punishment. A few innings each game, or for one game, then that’s discipline. It’s not going to break them. It can actually benefit them”.Unlike the use of exercise and benching, yelling in the form of critical, demeaning, or humiliating comments, was interpreted as a punitive method by all participants. Parents, for example, agreed that yelling was the worst method of punishment for an athlete to endure, leading to feelings of shame and embarrassment. Erica (parent) suggested, “yelling is probably the worst punishment the kids can experience on the field. No one ever wants to be yelled at…it’s such a shameful punishment. And it doesn’t work”. Further, Alyssa (parent) shared:Yelling is pointless…yelling is just an expression of your frustrations…[Son] would rather die than be yelled at by a coach. He just hates it. He’d be mortified to have a coach call him out in front of his friends. He’d quit baseball.The athletes agreed that yelling was a form of punishment and was a harmful and ineffective method of changing behaviour. Karim (athlete) compared the ineffectiveness of yelling at athletes to when he yells at his dog: “When I yell at my dog for barking, he’ll bark even more. Kids are the same. They won’t respond well”. James (athlete) expressed similar beliefs, suggesting that yelling may deter athletes from participating in sport: “Yelling doesn’t help, it just discourages people…That kind of punishment can scare kids away”.Yelling was perceived as ineffective due the potential negative outcomes associated with using this tactic. For example, Jim (head coach) stated, “Yelling is pointless. It serves absolutely no purpose other than discouraging kids. They may hate you. They may leave the team or the sport…yelling demonstrates an inability to communicate and lead, which we’re called to do as coaches”. In addition to producing feelings of animosity, yelling was perceived as eliciting fear of failure and anxiety, thus negatively impacting performance. Tim (athlete) commented:There’s already so much thinking in baseball and when I’m in a slump, I can’t help but think of the shit I’m going to get if I make a mistake. Sometimes I like when coach sits me in those situations because I’m afraid of getting yelled at if I make a mistake. I don’t want to sit, but I’m also anxious of getting hell after…I just hate getting yelled at.Laura (parent) stated, “yelling at them [athletes], makes it difficult for them to find the courage and drive to fight through the errors and the losses…it’s a bad type of punishment that can really affect the team”. Likewise, Phil (parent) shared:No, kids are not supposed to get yelled at because when you yell at the kids, what do you think is going through that kid’s mind? The next ball that goes to him he’s going to be so nervous that he’s going to try not to mess up, and that’s when he’ll mess up…if you yell at him, he’s going to go…have you seen a turtle? Right in his shell.Stemming from the stakeholders’ perspectives of the three common behaviour management strategies, and the apparent inability to distinguish between these as punitive and disciplinary, the participants were asked more generally about their conceptualizations of punishment and discipline. According to the athletes, parents, and coaches, punishment and discipline were interpreted as interchangeable; specifically, their responses highlighted the assumption that both approaches achieve similar ends related to behaviour change. For example, Diego (athlete) stated, “There’s not much of a difference…the goal is to change behaviour…punishment, discipline, it’s all the same at the end”. Eric (athlete) echoed similar sentiments, “I see it [punishment and discipline] as the same thing…I don’t see a difference. Both achieve the same thing…both are used to correct behaviour”.Many of the adult participants (coaches and parents) also suggested that punishment and discipline were similar concepts. For example, Patrick (assistant coach) indicated, “There’s no difference…Punishment, discipline, repercussion, consequence…it’s about stopping bad behaviour. If you can use a strategy that stops athletes from misbehaving, then it shouldn’t matter what you call it, as long as it stops the behaviour”. Similar to the athletes’ responses, parents associated punishment and discipline with desired outcomes . Phil (parent) stated, “they’re more or less the same to me…we’re getting picky about semantics now… Don’t they both do the same thing?” Likewise, Laura (parent) elaborated:Discipline is a branch of punishment. [Discipline] sounds nicer. It’s probably more politically correct to saying your disciplining a child than punishing. But it’s the same thing. Punishment sounds harsh, like you’re really cracking the whip. But don’t they both do the same thing? If I punish or discipline my child, the goal is still for them to learn right from wrong…so, it’s the same thing. They both work.Overall, the perspective that punishment and discipline were synonymous concepts was influenced by the participants’ belief that both methods achieve the intended outcome of behavioural change.In a few instances, participants claimed that punishment and discipline were different, but a very rudimentary distinction was provided, namely, that punishment was negative and discipline was positive. For example, Erica (parent) noted, “…discipline is to teach them a lesson…teach them the right way or teach them the way they shouldn’t be doing it…punishment is a harsher, more negative way of trying fix behaviours”. Beyond this superficial distinction, no substantive differences were conveyed.The current study investigated sport stakeholders’ understanding of behaviour management strategies within one competitive all-boys youth baseball team, including the identification of commonly used strategies and interpretation of these tactics as punishment or discipline. The findings in the current study provide insight about sport stakeholders’ views of punishment and discipline; of particular interest, the conceptual confusion of punishment and discipline highlights the need to educate coaches and other sport stakeholders on the importance of using developmentally appropriate disciplinary strategies at the youth sport level. Currently, there is a gap in Canada’s coach education system confronting the punitive, yet often normalized use of exercise, benching, and yelling. Increasing sport stakeholders’  awareness of behaviour management in sport may safeguard vulnerable participants  from maltreatment inflicted by harsh punishments.Across the stakeholder groups, responses highlighted that among several reported behaviour management techniques used on this baseball team, exercise, benching and yelling negative comments were the most common. All stakeholder groups believed that the administration of exercise in response to undesirable athlete/team behaviour was effective in obtaining athletes’ attention, teaching athletes that their behaviour was inappropriate, fostering mental toughness, establishing coach authority, and increasing youth’s ability to distinguish right from wrong, notions which have also been supported by research examining teachers’, teacher-coaches’, physical education majors’, and athletes’ perspectives on the use of exercise as a behavioural management method . However, these findings contrast with previous research that indicates exercise as punishment is associated with detrimental effects such as extreme fatigue, injury, impaired coach–athlete relationships, and negative perceptions of self , and resFor benching, different interpretations existed among stakeholder groups. Coach and parent responses suggest that benching can be an effective behavioural management tactic to address poor performance, build character, stimulate reflection, and encourage values, such as perseverance, sacrifice, and selflessness. Alternatively, athletes viewed this tactic as a form of punishment and one of the worst things a coach can do to an athlete. This finding is not surprising when considering playing time is one of the primary ways youth experience fun and enjoyment in sport . FurtherIn contrast to the findings pertaining to exercise and benching as punishment in which varying perspectives emerged amongst the stakeholders, all groups agreed that yelling negative comments was a form of punishment and had detrimental effects. The stakeholders reportedly viewed this tactic as an inadequate and harmful form of communication that may elicit feelings of low self-worth, fear, and stress. This finding is consistent with previous research that identifies yelling negative comments as a form of emotional abuse in sport , which iThere are several reasons to explain why the practices of benching and exercise may be normalized in sport, while yelling is not. It is possible that the use of exercise as punishment in sport continues as a common practice despite documented negative effects for athletes and despite position statements condemning its use because of its long-standing history of use in sport and its military roots ,52. The The practices used in competitive youth sport are undoubtedly influenced by the prioritization of outcomes such as performance excellence, including winning-at-all-costs approaches. Several researchers highlight the implicit and explicit cultures of control that exist in organized sport , which pThe results highlight a lack of understanding regarding punishment and discipline. Specifically, the participants failed to distinguish these concepts when interpreting the use of exercise and benching in sport, but instead suggested that these behavioural management strategies can be used as both punishment and discipline. In the few instances where participants acknowledged punishment and discipline as different, these interpretations did not expand beyond the general understanding that punishment was negative and discipline was positive. Some of the participants referred to conditions such as the length of time an athlete was benched, the duration and intensity of exercise administered, and whether pain was experienced to distinguish between punishment and discipline. Further research is needed to explore the conditions under which discipline is distinguished from punishment.In several interpretations, participants distinguished a tactic as punitive or disciplinary based upon the anticipated outcomes such as whether feelings of shame or pain resulted. The reliance on such outcomes to distinguish between punishment and discipline is problematic for several reasons. First, using outcomes of the method as the distinguishing feature means that the same behaviour could be interpreted differently across individuals and situations based upon the effects of the action. For example, the same exercise applied as punishment may have differential effects on the athlete depending upon physical fitness level. Further, punishment is not recommended because it teaches young people that adults have control over them, which also denies youth athletes the opportunities to learn important life skills such as self-control, problem-solving and independent thinking. Finally, a reliance on the outcomes of the methods precludes a preventative approach to harm of young people in sport . Given tThe inability of critical socializing agents in sport such as parents and coaches to distinguish between punishment and discipline is important for several reasons. The lack of clarity between punishment and discipline may limit stakeholders’ understanding of appropriate versus inappropriate behaviours, and without this understanding, harmful practices may be normalized and perpetuated. Further, the mechanisms of punishment, including the use of fear and control, may contribute to sport experiences for youth that are characterized by a lack of enjoyment and disinclination to continue sport participation ,47. The The findings in the current study provide insight regarding sport stakeholders’ understandings of behaviour management strategies used in youth sport as well as their interpretations of these practices as disciplinary and/or punitive in nature. This research may stimulate questioning among sport stakeholders regarding the use of punishment and more developmentally appropriate disciplinary practices in sport. Nonetheless, the findings must be interpreted within the context of the current sample, which consisted of stakeholders affiliated with the same competitive boy’s baseball team in a specific geographic region. The fact that the participants came from the same team and had similar experiences may have limited heterogenous responses.The stakeholders’ inability to distinguish between punishment and discipline indicates a need for education pertaining to developmentally appropriate behaviour management strategies. This need for education is heightened by the finding that the adults in the study often held positive views of punishment—an alarming interpretation given the plethora of evidence indicating the harmful effects of punishment ,21,22,23Several other areas of interest emerge for future research, including whether interpretations of punishment and discipline differ according to sport type, sport level, and identity variables such as gender, educational background, and years of coaching. Investigating the experiences of behaviour management among athletes with varying intersections of identity may expose alternative punitive methods or introduce more humanistic methods of discipline. Moreover, research exploring stakeholders’ perspectives of behavioural management strategies across different competitive levels could disclose an intensification of the utilization and endorsement of punitive measures under circumstances where there exists an amplified pressure to win.All the athletes, coaches, and parents agreed that exercise, benching, and yelling are the most common behavioural management strategies used in youth sport. While the participants commonly interpreted yelling as punishment, they struggled to differentiate exercise and benching as punitive or disciplinary in nature. For many participants, punishment and discipline were perceived interchangeably based upon the assumption that both approaches achieve the same outcome of behaviour change. For participants who perceived a distinction between punishment and discipline, their interpretations were often characterized by a rudimentary understanding of punishment as negative and discipline as positive. This research extends current youth sport literature by exploring sport stakeholders’ understanding of common behaviour management strategies used in youth sport as being punitive or disciplinary in nature. Overall, the findings highlight the need to inform the sport community about the importance of using more developmentally appropriate strategies to foster positive sport experiences for youth athletes.


All these studies suggest that melatonin may be effective in preventing the pathology of amyloid and tau protein and modulating the metabolism of the amyloid protein precursor. I have doubts about the suggestion that melatonin is “next vitamin D” [sic]. Does vitamin D have the therapeutic properties described above for melatonin?”We would like to thank Dr. Pluta for his thoughtful comments  on our rAs we stated in our article, there are several similarities between melatonin and vitamin D: “Both act as hormones, affect multiple systems through their immune-modulating, anti-inflammatory functions, are found in the skin, and are responsive to sunlight and darkness. In fact, there may be similarities between the widespread concern about vitamin D deficiency as a “sunlight deficiency” and reduced melatonin secretion as a result of “darkness deficiency” from overexposure to artificial blue light”. In other words, the two have overlapping functions and complementary activities related to light exposure. Additionally, both compounds decline endogenously with age ,4. They Our suggestion is not that one replaces the other, but that there may be some similarities in function. Furthermore, our intention in this review article was to provide a survey of multiple areas of clinical concern related to how melatonin and vitamin D may be involved in foundational mechanisms associated with a broad spectrum of disease pathologies, including their (1) anti-inflammatory activities ; (2) antWhat Dr. Pluta seems to be asking is how vitamin D compares with melatonin in relation to amyloid and tau protein pathology. In his comment, he cited several studies indicating melatonin’s proficiency in accomplishing many functions related to amyloid metabolism and inhibiting the tau protein’s hyperphosphorylation. While these are important hallmarks of dementia, we would like to offer a fundamental mechanistic view of neurodegenerative diseases involving the three aforementioned mechanisms. Specifically, copious research has suggested that inflammation is part of the underlying dysfunction that can ultimately result in or exacerbate the dysregulation, aggregation, and lack of proper elimination of amyloid and tau proteins ,19. MoreSeparate from the established and emerging research aiming to support the shared mechanisms of vitamin D and melatonin in brain- and neurological-related disorders, there is some indication that vitamin D may play a role in amyloid ,32,33,34In conclusion, we are grateful to Dr. Pluta for raising the question about the similarities between vitamin D and melatonin and whether the two may be seen as having identical functions, particularly for brain and neurological health. To reiterate, while we would not want to suggest that the two are interchangeable, we documented that they could target common mechanistic pathways underlying the pathologies of several chronic diseases and even foster healthy brain aging.