The introduction of mixed-income communities in public housing neighborhoods is a common revitalization strategy in metropolitan areas in North America. This study investigates student and teacher perspectives on safety in a Canadian inner city and marginalized neighborhood undergoing revitalization, alongside the redesign of a local school. The displacement of families and students, tied to housing relocation and student school mobility, resulted in increased concern around bullying, school safety, and displacement of place-based familiarity and social bonds. While most students felt safe at school, they were acutely aware of community level violence, criminal and gang activity in the neighborhood, and racial stereotyping. Students were also generally skeptical that revitalization would address the root causes of violence. The findings support the importance of including children’s voices when planning, implementing, and evaluating policy initiatives that directly affect their lives. Community safety is an important indicator of children’s well-being and healthy development . ResearcA meta-analysis of 114 studies on the effects of exposure to community violence found that witnessing or hearing about violent behavior in the community affects children’s mental health in terms of emotional regulation, traumatization, and fear for safety, although direct victimization more strongly predicts the development of symptomatology . NeighboThrough its negative effects on children’s psychological well-being, exposure to violence is thought to impair educational achievement , and mayMoving higher income residents into a low socioeconomic neighborhood has been found to be positively correlated with children’s educational achievement  and mentNeighborhood revitalization initiatives are also criticized for legitimizing gentrification and displacement, with many residents never returning to their newly redesigned mixed-income communities after the disruption and dislocation caused by redevelopment . For insRecent research on neighborhood safety have found the existence and prevalence of social ties and social cohesion to be more potent contributors to residents’ feelings of safety and their perceived risk of victimization in the neighborhoods e.g., . For exaIn terms of violence prevention and student safety within the physical boundaries of a school, it is suggested that violence, including physical fights and bullying, is a systemic and school-wide issue, involving more than the dyadic relationship between a perpetrator and a victim . Other rDiscussions of school violence, bullying, and victimization tend to be predominantly psychological, and the resultant psychological profiling of “bullies and victims” is believed by many researchers to impede our understanding of the true nature of violence as having social and political underpinnings . PerceptUnlike urban renewal efforts of the past, promising results of current revitalization initiatives in established urban neighborhoods requires some degree of input from the individuals affected by such programs . While uThe present study investigates student and teacher perceptions about safety during a Canadian neighborhood’s redevelopment  and the redesign of its local school. This research is part of a larger project that investigates how neighborhood redevelopment and school redesign influence student academic achievement and wellbeing. The present study focuses on student and teacher data from 2013 and 2014, in which school and neighborhood safety emerged as a salient topic. This adds to the literature on neighborhood revitalization and mixed-income communities by offering students and teachers an opportunity to voice their opinions about safety and security in the context of school and neighborhood change. The research helps us to clarify how social bonds and interactions can be altered as a result of a neighborhood redevelopment and students’ and teachers’ experiences with such changes. Finally, this study helps to improve our understanding of whether or not the process of neighborhood change, including mixed-income neighborhood redevelopment, actually contributes to the quality of life of longstanding residents, and in particular children, who have typically little or no say about the fate of their neighborhood.This qualitative study investigated student and teacher perceptions of safety while living or working in a neighborhood undergoing revitalization. The study and its activities were approved by the Research Ethics Board at Ryerson University and the External Research Review Committee of the Toronto District School Board. Focus groups were conducted with students and teachers at two school sites. Focus group audio recordings were transcribed and analyzed with thematic coding with a grounded theory approach . All datFocus groups were conducted with 148 students (2013 and 2014) and 45 teachers (2013), at two school sites located in the same inner city neighborhood. Participating students were 4 to 13 years old, in Kindergarten to Grade 8. Junior and Senior Kindergarten (JK/SK), for 4- and 5-year olds respectively, are part of the public education system in Ontario and elective enrolment is nearly universal. Elementary schools in Ontario typically include Kindergarten to Grade 6 or Kindergarten to Grade 8.At each school site, student participants were divided into focus groups based on grade level. There were three focus groups with age divisions referred to as Primary (JK/SK to Grade 2), Junior (Grade 3 to Grade 6) and Intermediate (Grade 7 to Grade 8). A total of 25 student focus groups and 8 teacher focus groups were conducted, with separate focus groups for students and teachers. A total of 25 student focus groups with 148 child participants ages 4 to 13, and 8 teacher focus groups with 45 teacher participants were conducted.In 2011 and 2012, a public school (RS) located in a socioeconomically disadvantaged neighborhood in downtown Toronto was closed to undergo a school redesign and rebuild. During the school redesign, which included changes to the built environment and the addition of an attached community center, students and teachers were relocated to two “feeder schools” (FS1 and FS2) in the same neighborhood. RS students in Grade 6 to Grade 8 moved to FS1, a Kindergarten to Grade 8 school. RS students from Kindergarten to Grade 5 moved to FS2, a Kindergarten to Grade 6 school. Some RS staff moved to FS1 and others moved to FS2. The RS students and staff remained at FS1 and FS2 until March of 2013. At this time, FS2 was closed, and students either went to FS1, or to RS. Teachers dispersed similarly, with some going on to work in other schools.Throughout the school redesign process, a mixed-income initiative had been ongoing in the neighborhood since 2003, wherein old social housing units were being demolished and upgraded. Prior to redevelopment, the neighborhood was designed in the mid-20th century with low-rise buildings surrounded by park spaces and walkways, with no through streets for traffic . RedevelAll data in the present study were gathered through focus groups carried out at the Redesign School and Feeder School 1 in the Spring-Summer of 2013 and 2014. A semi-structured focus group method was selected because it allows facilitators to have a predetermined focus, while allowing participants to freely draw on personal and shared experiences. This allowed for a rich discussion between participants, building on one another’s comments . With a Research team members reviewed verbatim transcriptions of audio recordings from focus groups and used inductive thematic analysis, informed by a grounded theory method  to categWhile the majority of students did not report feeling unsafe on the premises of their school, most students did have something to say about safety within the school and/or in the community that related to ongoing neighborhood change.At RS, both returning and new students generally felt that the school provided them with an enhanced sense of security, in comparison to their feelings of safety within the community at large. For instance, returned RS students felt that the new, better security cameras ensure a feeling of security. One student said that there are less violent incidents since the redevelopment began, but that violent activities still occur. Other students noted that they feel safe in RS because they “have friends that back [them] up” and because RS has “good security” . When discussing what characteristics of RS make them feel safe, students specified: alarms, emergency lights, sprinklers, smoke detectors, and easy places to hide if there is a lockdown, such as a classroom, a locker, or a washroom. When asked if they felt safe at school, one student responded: “Ya, there is cameras, there is security guards” . Students noted their previous schools (FS1 and FS2) were different because there was “no place to hide” during a lockdown, fewer exits, and the sprinklers were “rusty and old” . The majority of students reported feeling safe in the gym, classrooms, and closets.Some students said fewer fights occur at RS than at schools they had attended previously, such as FS2, and they felt safer due to the new equipment and play areas. One student explained: “I think it’s more safe [at RS] . . . Yeah there’s not, like, gun shots and stuff.” . One student said the teachers at RS played a key role in school safety: “I feel safe because the teachers and the principal always reassure us and tell us that we are safe here and they make us feel safe” . Teachers at RS reported concerns about student safety tied to ongoing construction in and around the school.Despite those who reported a higher level of safety within RS, a large number of students reported that the level of safety decreased in RS, partly due to perceived greater permeability of the building and grounds, and partly due to the violent behavior of some individuals in the neighborhood. RS students were concerned that people could see into the school through the windows, doors were too easy to get into, playgrounds had no lockable gates, and the building construction adjacent to the school was ongoing. One student at RS remarked on the glass windows: “Five layers of glass. Glass all over. . . . in the windows. . . . Because, like, if there’s a bad guy, maybe people could break through” . Similar feelings of trepidation were shared by others at FS1 who reported an incident where a window was broken at the school by someone trying to break in, and a story about a person with a knife stabbing the school window . These feelings about the school’s perceived permeability were echoed by some RS teachers. Teachers at RS described the library, which is built from large glass panels, as being “almost too exposed” . Some teachers expressed concern that in the event of a lockdown, “there is nowhere you could put kids where they wouldn’t be seen” , and some noted that as a result, they advocated to have blinds installed and some windows frosted. Teachers noted that the later installment of blinds generally helped to increase feelings for protection. Other students said that because there were a lot of “bad people”  in the neighborhood, they did not feel safe in the school or in the neighborhood.At FS1, students had similar mixed perspectives on safety. Many students reported feeling safe due to the presence of teachers, security cameras, and the physical security of the school. Students reported that they felt safe in places like the classroom and the office. One student at FS1 explained, “I feel safe at my house, but I’m so, so safe at the school. I don’t feel safe outside” . At FS1 where the school library does not have large panel windows, one student shared, “I feel safe in the library because of the shelves. You can hide back there and go ‘I’m safe’” . Some students, however, said that they did not feel safe in other areas of FS1, including the washrooms, the staircases, and near large windows. They described bullying, lockdowns, and shootings nearby, as reasons for their feelings of lack of safety.Overall, aspects of the newly redesigned school environment seemed to play a role in students’ feelings of safety  and lack of safety at RS , with mention of concerns regarding neighborhood violence and school lockdowns at both FS1 and RS, and speculation from teachers regarding the role of neighborhood construction tied to redevelopment in student safety.There’s just so much fights [at FS2] and some of the people . . . like the first time I went there, some of the people I knew for a long time, but some of them when I went there, they all looked at me, like, ‘Why are you coming here?’ and all that, ‘Go back to your other school. . . . We don’t need you here.’ And ‘Oh, since the RS kids came here it’s all like been so boring, it’s not alive anymore.’ And that made us feel like, sad .Given the unique circumstances relating to the ongoing construction work and changing structure of the neighborhood, including disruption of place-based familiarity and social bonds, new relationships and situations evolved that may have fostered bullying and victimization. For instance, during the move to FS2, one student remarked on the frequency of fights and heard comments that were rejecting and perhaps intimidating:Every single little thing you say will, like, get you in a fight . . . Like in our class, like, there are all these bullies. Like it wasn’t really pocket knives, but it was those knives that you cut wires for or something like that. They brought it. . . and they came, two of them. One of them was purple and one of them was pink and the teacher had to take it .Students also referred to the role of adults, including the principal and their teachers, in alleviating bullying incidents. For instance, one FS1 student noted,The teachers they don’t know who to turn to for help. Sometimes the teachers they get scared because the other kid threatened them [by saying]: ‘If you say this or this I’m going to hurt you’. . . . The teachers just got used to that whole thing – like, [in] today’s age and day, teachers got used to kids being shoved around .Another FS1 student felt teachers were intimidated themselves and had become acculturated to a certain amount of inter-student bullying:Some of the bullying was racist or based on students’ religious beliefs. For instance, one student at RS noted, “Before this year in the other school, a kid he was making fun of [Islam]. We were, like, ‘Why are you going to do that, we never made fun of your religion’” .Bullying was seen to be a pervasive problem amongst students in all the neighborhood schools. Many students complained about incidents of bullying that they experienced or observed, including some primary students at RS who indicated that there were “lots”  of bullies at the school, and that many of the bullies were in older grades. Most students agreed that involving adults  was a good way to combat different forms of bullying, despite the general perception among students that educators make little difference in reducing the prevalence of bullying. Although teachers did not explicitly discuss bullying in the school setting when they retrospectively spoke about the transitional period, teachers did report a “rivalry” between students during the transition. One teacher acknowledged that there was tension between the two student bodies and said that students would “label” one another as being RS or FS students.I really felt when I first came to this school – and maybe it’s me becoming better at managing my position – but I really felt like it was a lot more sense of urgency all the time, a sense of scrambling, like there were always incidents. There were big incidents. There were big fights, things like that. . .the behavior piece was a big part of your daily job. I feel like that has really improved, like hugely. I believe our number of suspensions is down. I know that the number of office referrals is way down.Fights in the school setting were reported by a number of students. One student said that fights often broke out on the basketball court at FS2, with another student from RS stating, “[On the basketball court] I was kind of afraid because I saw more fights over there and people were doing dangerous things” . One student remarked on the level of ‘strictness’ of school administrators, connecting ‘stricter’ administrators with fewer school fights, and sharing perceptions of differences across schools. Bullying can instigate or escalate to physical altercations. One student talked about being bullied by FS2 students and describing a fight that broke out as a result. Another student at FS1 said that fights were common in the neighborhood along with other types of violence, and that: “Kids are getting hurt and stuff—every day,” with some children “ganging up” against one another . The neighborhood schools implemented programing to help remedy issues tied to violence. For example, one student at FS1 referred to the existence of anger management classes, and other students revealed, “I’m in one of those classes” . Similar to situations of bullying, students had mixed perspectives about whether educators were effective in preventing or stopping fights. For example, one student described teachers as, “just, like, standing there and watching,”  while other students suggested that having more teachers attempt to deescalate situations was helpful. A teacher discussed the transition into RS (2013) in relation to behavioral incidents saying,A number of junior and intermediate students in both FS1 and RS spoke about gang activity in the community. Students’ perceptions of gang activity in the neighborhood were mixed, where some felt the presence of gangs had diminished, and others felt gangs in the neighborhood were active. The students who felt that gang activity had diminished explained that “[there] used to be gangs really bad” , with suggestions that a lot of the gang members had died. Referring to the neighborhood’s impact on the school climate, some students suggested that there were fewer gangs in the area near the school, but others disputed this claim. Some students said that gangs were still active in the neighborhood, that they knew of individuals still involved in a gang, and that some gang-related activities had simply relocated. Other students mentioned school lockdowns, gang-related behaviors and criminal activities in the area as reasons for feeling unsafe in school.When asked whether the redevelopment efforts (which include new youth projects) were changing gang activity in the neighborhood, one student was adamant, saying, “No. They might be changing [the neighborhood], but they are not going to change the people that are here” . One educator (2013) suggested that since the revitalization, “young kids are getting into things at much earlier ages whether its weapons, robbing, stealing,” as gangs have become “disjointed” and “everyone is kind of vying for different positions.” Other teachers, were more hopeful, pointing to new employment opportunities due to neighborhood redevelopment, because “that’s a big issue for kids, choosing to work versus gangs and drugs”.However, some students were skeptical that all forms of violence occurring in the neighborhood were gang-related. One student suggested that police officers’ investigations may be based on stereotypes and the quick assumption that some forms of violence are gang-related. The student described a specific situation where someone died in one of the buildings in the neighborhood, saying, “There’s somebody that passed away in one of the buildings, and they were like, ‘Oh it was gang-related’, [but] it wasn’t at all. They just thought it was because of how he looked and everything, his hair and this and this and that” . In response to this, another student said, “it’s not fair” . Gang activity in the community was a salient topic of discussion among students and teachers, with skepticism from some students that redevelopment reduced gang activity, and others alluding to unfair assumptions of gang activity due to profiling.When I moved here [to RS] I was mad because, well, like the reputation they had.. . . They [former school friends] don’t like this school. They told me so much different things about it, but when I came here it was so different, and, like, here I am the same person I was back then . . . ‘cause I have the same personality, I haven’t changed .Some junior and intermediate students remarked on issues of territory in the neighborhood and rivalry between schools, with the different groups of students coming together in RS and FS1 due to school redesign. One student referred to the turf-based rivalry that exists between different schools and how that initially prejudiced her feelings about moving to RS:Because of what she had been told, she was angry, upset, and wary during her initial time at RS, but reported that she quickly got over that and then liked the school.I am incredibly surprised about how well it has gone. One of the big changes that we were worried about when we moved out was this whole idea, this notion of south and north. . . and that you don’t cross the lines. But the kids really did surprise me, which goes to show sometimes we have these perceptions. That we worry about them and in fact it is fine.Teachers also commented about rivalries across the different areas of the neighborhood. One teacher noted, “Rivalries between north and south [areas of the original social housing development] were very real” . However, the social and spatial dynamics have shifted with the influx of students in the newly redesigned RS. Another teacher at RS (2013) noted,A number of students at both schools believed that the rate of crime in the neighborhood had not been reduced as a result of revitalization. In particular, they were upset that shootings still took place, saying that shootings happen “every other month” . Another student reported, “I saw on TV that somebody [shot] somebody in the car and the car crashed” . They also referred to the lockdowns that have happened at RS, as well as the people in the neighborhood who yell at children. They noted the various places in the neighborhood where people have died from violence. One student talked about shootings starting up in the neighborhood again: “Before there were lots of shootings and then they stopped for a bit, now they are back” .We have circle time [with students] – you can call it whatever you want, but we basically talk about how our weekend went and whatever is on their mind. . . such as somebody not wanting to leave their apartment because somebody is dealing drugs outside, or they are just not allowed to go outside because there is nothing for them to do there. One of the parks they go to. . . there is often people with mental health issues and [addiction], so a lot of parents and guardians choose to not let their child have some freedom in that sense.Educators also remarked on the extent of criminal activities and vandalism within the neighborhood. For example, one educator  said:Junior and intermediate students speculated about safety in the broader community. When asked whether violence in the neighborhood had changed as a result of the revitalization process, one student said, “It hasn’t changed,” but the student noted that media reports on violence no longer “say [the name of the neighborhood] because they want people to move in” ; instead, the address or the name of the building is often provided. Another student agreed that the level of violence in the neighborhood has remained the same since neighborhood redevelopment began. Some students noted, “the roads are open [due to redevelopment] for the police cars to go in or out. . . but they’re still not catching anyone” . Other students noted that the level of violence has been “better since 2005. . . but it’s not gone” .There’s going to be more violence happening. . . You’re bringing in people from different neighborhoods against us. We’re not saying that we are harmful to them. They must feel offended by us and try to do something to us that’s causing more violence.One student (2013) suggested that the relocation and introduction of new people due to redevelopment would instigate conflict between original and new residents, suggesting class enmity, with incoming residents perhaps looking down upon longstanding residents:The forced relocation of residents during neighborhood redevelopment construction concerned some students. Remarking on safety concerns, one student noted, “[it] doesn’t make sense,” because it will create “more violence in another area” . The significance of territory was raised again when a student noted, “they may shoot you or something” because you cannot mix neighborhoods, and when people know you are from this neighborhood, they will say, “I don’t like you” . Another student suggested that you cannot just “throw” this neighborhood’s residents into a new community, but rather, the move should be done slowly.The ongoing construction work itself raised concerns about safety among students. For example, an intermediate student (2013) said that neighborhood redevelopment is “dangerous,” noting that a playground was closed because of safety concerns due to construction. Students reported windows being smashed with rocks in empty buildings slated for demolition, that there is increased air pollution due to construction, and that the community is “dirty” and “gross” . Some new buildings, students explained, have a pass key to enter while others have a front desk with security staff where visitors must check in. However, many students noted that the security in their own building is low, with one student saying that his/her building has a security officer, but he is rarely ever seen. Students shared their concerns about safety in the broader community, discussing their perspectives on the stability neighborhood violence, social mix, describing neighborhood construction, and building security.Students and teachers both attested to the multifaceted nature of violence and safety issues in the different areas of the neighborhood, especially within the spatial boundaries of public schools. Students were generally skeptical about the positive effects of neighborhood revitalization on safety, citing the possible relocation of violence to different areas of the city and potential rivalry between longstanding and new residents in the neighborhood. Students even reported newer forms of violence that may not have been present prior to neighborhood change, including clashes between longstanding and incoming students at feeder schools, and vandalism tied to construction. Student and teacher perceptions of safety within the context of neighborhood revitalization were generally consistent with the literature on the effects of neighborhood change initiatives on violence. Specifically, students were pessimistic about reduction in violence , and theStudents, however, felt safer in school than in certain areas of the neighborhood, partly due to the installment of new security measures. This does not correspond with the findings of The prominence of social ties as an indicator of feelings of safety and security in our findings most notably corroborate the arguments made by The transitional relocation of students to feeder schools during the redesign of RS resulted in some students feeling unwanted and unsafe due to alienating remarks made by feeder school students. Students’ ability to trust one another and to form new relationships may be negatively impacted by their continuous exposure to violence in the community . HoweverBoth students and teachers were acutely aware of the occurrence of neighborhood crime, with many perceiving the prevalence of criminal activities to have remained steady even after changes were introduced in the neighborhood. As suggested by Students also noted that they felt the new residents would look down upon longstanding residents and could sense that new residents were “offended” by longstanding residents’ presence. Students commented on how the media reported building addresses rather than using their neighborhood name, demonstrating an effort to develop a new post-redevelopment neighborhood identity. Students noted that the underlying causes of violence in the neighborhood are not addressed by neighborhood redevelopment e.g., . For exaIncluding children’s voices is a necessary step when planning, implementing, and evaluating policy initiatives that directly affect their lives. This study describes student and teacher perspectives on safety in an inner city and marginalized neighborhood undergoing revitalization, alongside the redesign of a local school in the same neighborhood. The displacement of families and students, tied to housing relocation and student school mobility created increased vulnerability of students to bullying, safety concerns at school due to construction and the design features of glass panels, as well as the displacement of place-based familiarity and social bonds. Despite this, the majority of students felt safe on the premises of the school and noticed the security measures in their school surroundings. Furthermore, junior and intermediate students were acutely aware of community level violence, noting gaps in building security, criminal and gang activity in the neighborhood, along with perspectives on racial stereotyping, and the mixing of longstanding and new residents in the neighborhood. Students were generally skeptical that neighborhood redevelopment would address the root causes of violence. Given the strong empirical support for the role of community safety in students’ psychological well-being and educational achievement, the findings highlight the importance of community ties in helping to foster feelings of safety and security within the context of neighborhood change and have implications for programing, practice, and policy.


Many articles discuss the limitations of prediction methods and of the datasets used to train them, which result in low reliability for actual applications despite globally capturing trends. Here, we review these and other issues by analyzing one of the most detailed, carefully curated datasets of melting temperature change (ΔTm) upon mutation for proteins with high-resolution structures. After examining the composition of this dataset to discuss imbalances and biases, we inspect several of its entries assisted by an online app for data navigation and structure display and aided by a neural network that predicts ΔTm with accuracy close to that of programs available to this end. We pose that the ΔTm predictions of our network, and also likely those of other programs, account only for a baseline-like general effect of each type of amino acid substitution which then requires substantial corrections to reproduce the actual stability changes. The corrections are very different for each specific case and arise from fine structural details which are not well represented in the dataset and which, despite appearing reasonable upon visual inspection of the structures, are hard to encode and parametrize. Based on these observations, additional analyses, and a review of recent literature, we propose recommendations for developers of stability prediction methods and for efforts aimed at improving the datasets used for training. We leave our interactive interface for analysis available online at  Quantitative prediction of the effects of mutations on protein stability is a yet unsolved problem of key relevance in structural biology, molecular evolution, and protein biotechnology –8 and paThe most important datasets of protein stability effects upon mutation, combining both ΔTm and ΔΔGu data, have been derived by curation and literature-based completion of the ProTherm  and TherA recurrent problem in the field of mutant stability prediction is that even though every new program or server claims superiority over others reporting good correlation coefficients and low mean-square errors between predicted and known ΔΔGu or ΔTm, subsequent tests by third groups always reveal poorer performances. The latest such evaluations , 15–18 cWhile oligomerization, membrane integration or association, disordered regions, and other features naturally complicate protein stability predictions, the works mentioned above show that the problem of stability change prediction is still far from solved even for small, soluble, monomeric, well-folded proteins. Beyond the pitfalls in the training datasets and in the methods themselves as summarized above and discussed in many works, in this review, we focus mainly on the structural subtleties that lead to special situations of strong stabilization and destabilization as judged by ΔTm and based on high-resolution structures. We pose that these structural subtleties likely confuse the otherwise clear trends that can be modeled with simple physicochemical descriptors of the amino acid substitutions which is what most methods and programs do. Analysis of such situations in turn highlights very important aspects of having complete datasets well-balanced over all possible amino acid substitutions and structural situations. These analyses shall be of special interest to method developers, to protein designers, and structural biologists in general, to efforts aimed at improving datasets for training stability predictors, and possibly also for educational purposes., probably even harder for automated methods. Along the way and especially by the end of the review, we also elaborate on possible routes for future improvements of methods for stability prediction upon mutation and, of key relevance, of the datasets used to train them.We base our review on one of the most complete, carefully curated datasets of Tm change upon mutation, published by Pucci, Bourgeas, and Rooman in 2016 . AlthougStaphylococcus nuclease at 8%. This dominance of one particular protein type and Tm values pose a potential bias, present in most databases that compromises the quality of the dataset and its usefulness to train predictive models of mutational effects on protein stability. In principle, however, a sufficiently general model should not be very sensitive to this problem, as long as it is developed only for prediction on small, soluble, well-folded monomeric proteins with good structures available. However, as discussed in the works commented in the Introduction, in practice, this has not been much the case, with predictions failing importantly on proteins that were not part of the training and validation sets used to train the different methods, only somewhat useful to capture some of the strongly stabilizing and destabilizing mutations.The dataset by Pucci et al. contains full ΔTm data for 1626 mutations (hence “S1626”) from experimental measurements in 90 globular proteins of structure known at high resolution, all compact, globular, monomeric in solution at least in their wild-type forms, and known two-state folders. This, as opposed to other larger datasets that include oligomeric and transmembrane proteins, or that lack high-resolution structures or even lack structures at all, or contain only ΔΔGu data, etc., which might be useful too but do not provide a sufficiently clear basis for our analyses. Each entry of S1626 contains Tm and ∆Tm relative to wild type, flagged with the experimental techniques and conditions used to measure them, and in many cases also extended parameters that further describe the impact of the mutations on protein stability such as changes in folding free energy, enthalpy, entropy, and heat capacity. Stability measurements as close to neutral pH as possible were chosen upon construction by Pucci et al. when multiple options were available; in practice, 50% of the entries are at pH 6–8, 13% above pH 8, and 37% below pH 6 including some 20% of the total at pH 3.5 or lower  followed by differential scanning calorimetry  and fluorescence FL, 18%), with the rest measured through enzymatic activities, absorbance, and other methods , the ∆Tm values are all < 5 °C Fig. D. AnotheMcGuinness et al. also reported that, in S1626, residues in beta conformation are more sensitive to mutation compared to other secondary structures, having a more negative average ∆Tm, and that ∆Tm values for residues in coils display a large number of outliers at both positive and negative extremes . A closeIt is clear from its authors and from the analysis by McGuiness et al. that the S1626 dataset does not smoothly cover all possible amino acid substitutions. We have analyzed this in some more detail in Fig. Using their dataset, Pucci et al. developed two methods to directly predict ∆Tm upon mutation, which is more directly interpretable and practical than ΔΔGu predicted by most other methods. Their (Tm-)HoTMuSiC models  combine We also evaluated our neural network against the “prospective” data on guanylate kinase by McGuiness et al., to find that, just like with the models they evaluated, the network has rather limited predictive power for individual mutations Fig. A. It achhttp://lucianoabriata.altervista.org/papersdata/proteinstability2021/s1626navigation.html on any device. For each possible mutation from one amino acid to another, the app displays plots that resolve ∆Tm against three features of the reference residue as in the structure: RSA as a cue for solvent exposure, average B-factor of its atoms as a proxy for flexibility, and secondary structures simplified from DSSP assignments to either alpha, beta or coil at + 1, − 1 and 0, respectively.To explore the entries of the S1626 dataset in exquisite detail, we built a web app  and its magnitude by the size of the data point. In all plots, hovering over the data points (with a mouse in computers only) displays additional data. Thanks to a built-in JSmol  library,At a prediction accuracy similar to that of Tm-HotMusic, an advantage of our network is that it uses simple inputs and runs extremely fast. Thanks to this, we could sample and tabulate all 3 × 11 × 14 = 462 possible combinations of secondary structure , RSA (from 0 to 1 every 0.1 units), and average B-factor (from 10 to 140 every 10 units) for each of the 20 × 19 = 380 possible amino acid substitutions. We integrated these 380 × 462 = 175,560 predictions into the web app so that users can visualize them overlaid (as black dots) onto the raw entries for each amino acid substitution in the S1626 dataset resolved against RSA, average B-factor, or secondary structure , it can then reasonably interpolate and extrapolate the effects of mutations that are underrepresented or even not represented at all in the dataset. For example, mutations from Asp or Glu to the big hydrophobic Phe, Leu, Val, or Ile are dominated in the dataset by neutral and stabilizing examples, although one would expect such mutations to be rather destabilizing. As we discuss later, unfortunately these entries come from very similar substitutions in only a few proteins and represent mainly specific effects. Despite the dominance of positive values for the mutations, the network does deliver rather destabilizing predictions as expected Fig. B. The neIn this section and Figs. The first set of examples concerns S1626 mutations from glutamate to alanine, in which ∆Tm values span from roughly − 9 to + 8 °C including a larger fraction of destabilizing and neutral mutations over stabilizing cases  except for one case at − 7.5 °C, Glu107 in 1SHF. This is in a quite buried loop, establishing hydrogen bonds that stabilize closure of the domain; thus, it is not surprising that mutation to Alanine is very destabilizing Fig. D. The otBut not all cases are easy to explain. For example, Glu48 of 2RN2, quite buried, looks like a stabilizing element as it forms hydrogen bonds with Asn44 one helical turn away and with Ser71 coming farther in sequence. Although this situation is quite similar to the one just discussed, here mutation to Ala is nearly neutral with ∆Tm = − 1 °C with no apparent obvious explanation  predicted from wild type to mutant and vice versa should be of same magnitude and different sign. As Pucci et al. showed, this is hardly the case for most ΔΔGu predictors, a problem that stems in the bias of training datasets towards destabilizing mutations  to whichLast, an obvious, important conclusion of our analyses is that methods that treat structure explicitly have better chances of capturing the complex structure-dependent effects of mutations on (de)stabilization. As we have shown through examples, this might be important especially for mutations from and to amino acids of drastically different volumes and, not minor, may be important already for changes that induce |ΔTm| of already 9–10 °C, i.e., quite before the usually accepted limit of 20 °C. Properly modeling structural perturbations induced by mutations are far from trivial yet critical, because as many of our investigations show a simple backbone displacement or rotamer can change whether a hydrogen bond is lost, gained, or swapped. The incorporation of molecular dynamics simulations is enticing, especially as force fields evolve , becauseYet it is important that many caveats will still stand even if we get very detailed, complete datasets and employ complex methods based on simulations; for example, changes in stability originated by changes in oligomerization states  will be very difficult to account for, because not even the most complex simulations can capture this correctly. Homology modeling at very high sequence similarity, i.e., essentially a problem of sidechain rotamer optimization, seems today to work quite well to predict melting temperature change. However, homology modeling already at sequence similarities under 98% already results in quite substantial loss in the quality of predictions .


Obesity is a serious public health concern in the Gulf States. Students are exposed to many unhealthy weight-related behaviors due to college life. However, research that gives insight into regional and culture-specific aspects and determinants of weight-related behaviors in students is lacking. The purpose of this study was to explore the potential determinants of weight change, eating behaviors, physical activity, sedentary behaviors, and sleep behaviors in Saudi university students. Five semi-structured focus group discussions guided by Social Cognitive Theory were conducted, consisting of 33 male university students 20 to 22 years old. The data were transcribed, coded, and organized according to themes. The students reported weight gain due to personal, social, and environmental factors related to university lifestyle, such as unhealthy eating behaviors, low physical activity, high sedentary behaviors, and inadequate sleep. Both eating behaviors and physical activity shared similar personal aspects found in other studies, such as knowledge, stress, lack of time, and lack of motivation. However, there were some unique social and environmental factors in the region, such as the social norms, cultural aspects, weather conditions, passive transport dependency, and khat consumption, compared with studies worldwide. Such differences are key factors to developing effective interventions in the future. During the last four decades, overweight and obesity rates have increased in the Gulf States to an epidemic level . OverweiRecently, we performed a systematic review of the studies on correlates and interventions for overweight and obesity or weight-related behaviors among adults living in the Gulf States . CorrelaQualitative research in other regions of the world has indicated that eating and physical activity behaviors are determined by individual factors, social networks, and the environment ,7,8,9,10A factor that has been shown to lead to weight gain and to changes in weight-related behaviors in the Western world is the transition to college life ,7,8. ThiAn in-depth investigation is needed in the Gulf region to better understand regional and culture-specific aspects and determinants of weight-related behaviors. This understanding may feed the development of suitable and effective health promotion interventions. Therefore, the aim of this study was to explore which factors influence Saudi university students’ weight change, eating behaviors, physical activity, sedentary behaviors, and sleeping behaviors using a qualitative study design. Social Cognitive Theory was used as the guiding theory; this theory considers human behavior as the result of personal, social, and environmental factors and their interactions .A qualitative study design using focus group discussions was conducted for the data collection. The study followed the “Consolidated criteria for reporting qualitative research (COREQ)” guidelines . Focus gEthical approval (REC39/4-S003) was obtained from the Scientific Research Ethics committee at Jazan University prior to approaching the participants.Fliers, posters, word of mouth, and social media were used to recruit participants. The only inclusion criteria was that participants had to be male . Five focus groups were conducted with six to eight participants each. After the moderator’s presentation of the study and its objectives, the participants were asked to introduce themselves briefly, including age, study discipline, year of study, and living situation  at the end of the discussion.Audio recordings of each group discussion were transcribed in Arabic by the main researcher AB and double-checked by co-researcher MJ (both AB and MJ are native Arabic speakers). Quotations, sentences, or words of the transcripts were manually labelled with codes by AB to identify key concepts while preserving the context in which these concepts occurred. Then, codes were inductively clustered into themes and categories that were compared and discussed to give an overview of the main issues raised in the focus groups. Then, the analysis, theme organization, and structuring were checked by MJ., and AB and MJ discussed thoroughly whether the identified themes justified the issues raised in the focus groups. Disagreements were resolved in these discussions. By selecting, rearranging, and clustering the themes and subthemes, a reduction in the number of categories was finally attained.The results of the focus groups are presented by the themes that were discussed: weight change, eating behaviors, physical activity, sedentary behaviors, and sleeping behaviors. When relevant, the determinants influencing these behaviors are grouped into personal, social, and environmental factors. (See My cousin gained 10 kg or more since he went to university. Most students who I know have gained weight since enrolling in university” (Fourth-year student). “Almost all of our meals are not healthy. Food such as Kabsah and Marsah  unfortunately contain a lot of saturated fats” (Second-year student). “We know a lot of students who are lazy in general. They don’t want to be physically active” (Fourth-year student). Moreover, students tend to eat heavy meals late at night. “A lot of students eat late at night because they get hungry. It is very common for students to get fast food like burger, fried chicken, or pizza at midnight” (Third-year student). Some participants stated that losing weight can also be experienced due to studying stress and not eating. “I lost weight especially in the preparatory year because of the stressful schoolwork during that period. Some of my friends did too” (Second-year student).The participants indicated that many students gained weight in the transition to university, due to many factors related to university lifestyle such as unhealthy eating behaviors, low physical activity, high sedentary behaviors, and inadequate sleep. “Many participants stated that their eating behaviors had worsened since attending university. “I think that students do not have healthy diets. I have tried to follow a healthy diet, but there were obstacles that I faced as a student, and I think that all students face them. These obstacles can affect us, especially during exams period when unhealthy eating behaviors increase the most” (Fourth-year student). “We used to eat at specific times in high school, but now we don’t have a regular schedule anymore” (Second-year student).It is okay to eat unhealthy food, but you have to make up for it by being physically active” (Fourth-year student). “I do not have obesity or any other medical condition, so nothing holds me back from eating. Anything you eat, your body will benefit from somehow” (Second-year student). In addition, the students lacked awareness regarding the importance of healthy food. “Students, including myself, are not aware of what we eat. As long as it tastes good, we don’t care” (Third-year student). Some participants assumed that most students from different colleges other than the health-related ones lack knowledge about healthy eating. “I know more about healthy food because we learn about it in our college unlike students from different colleges where learning about healthy food is less important” (Fourth-year student). “Being in the field of health education has increased my knowledge unlike others and therefore influenced my eating behavior positively. Also, I was able to influence my family to make healthier choices.” (Second-year student). “When you know about the benefits of eating an apple, you are more likely to choose it over other unhealthy snacks” (Fourth-year student). However, some participants believed that knowledge alone cannot change behavior. “The behavior has to become a habit and the society as well as the environment play a role no matter how much knowledge you have” (Fourth-year student). Most students talked about the lack of intentions to eat healthily. “Not a lot of students intend to eat healthy. They just eat what is available” (Third-year student). In addition, the students think that motivation can play a major role in dietary practices. The majority agreed that students lacked motivation to eat healthily. “Nothing motivates me to eat healthy” (Second-year student).The students lacked knowledge about healthy eating. Some stated that individuals can eat anything they want as long as they are physically active. “Unhealthy eating behaviors tend to increase during exams period” (Second-year student). Skipping meals was very common with a stressful schedule. One of the participants told us that he had not eaten anything yet due to an exam he had to take, and it was noon already. Some students talked about overeating. “Many students tend to overeat when they skip a meal because they get so hungry” (Third-year student).University is very stressful, more so than high school as the participants stated; intense schoolwork and exams cause a lot of stress. Most students strongly believed that eating choices during such stressful periods can be affected negatively. “Healthy food preparation takes time, and being single doesn’t help because you don’t know how to cook. So, you just end up getting a burger or tortilla really fast because your time is very limited” (Second-year student). “If you are in a hurry, you just take anything on your way without thinking” (Third-year student). Furthermore, living far away from the university can take a lot of time. Many students live off campus, and they drive a long distance from the university to their homes. Some students live in nearby villages and drive more than one hour to the university every day.Students mentioned that lack of time was a major factor influencing dietary habits. “If you notice university students who follow healthy diets, most of them are physically active” (Second-year student). “What is the point of exercising and not eating healthily?” (Second-year student).Some students stated that if you exercise regularly, you are most likely to choose to eat healthily. “It is hard to follow a healthy diet when you are surrounded by family and friends who don’t because you eat with them all the time” (Fourth-year student). They mentioned that living with their families limited their eating choices because they mostly eat what is being offered.The majority of students lived with their parents or friends. They mentioned that family members and friends can impact their eating behaviors negatively. “I never eat here unless I really have to. I prefer to eat at home with my family or off campus with friends.” (Third-year student). “If the university provides healthy food, students will change. They will definitely eat on campus and not outside. Students will be more aware because of those changes” (Second-year student).The students discussed the lack of available healthy food in general. Canteens serve mainly fast food, sugar-sweetened beverages, and unhealthy snacks. Fresh fruits and vegetables, yogurt, and whole grain or wheat bread are not available. There are no opportunities to practice a healthy diet. Most students try to avoid eating on campus. “I eat here because there are no other options. I don’t have a car to eat somewhere else” (Second-year student). Some students indicated that there are several healthy options if you choose to eat off campus. However, the long distance along with the high prices make it more challenging for students to eat there.The main means of transportation in the university and Jazan city is the car. Some students cannot afford to have a car or call a cab, so they end up eating on campus. “Traditional FoodTraditional food in Jazan is not the healthiest, but we definitely can’t resist having it. It tastes very good” (Fourth-year student). “I tried to avoid eating Marsah (type of dessert that contains a lot of fat) for two weeks, and I totally regretted it because I did not benefit from that” (Second-year student).Some students talked about traditional food in general, and how attached they are to these dishes. “Social GatheringAnother aspect the students mentioned was social gatherings and the effects on the community. In these gatherings, plenty of food is served in very large quantities in order to show generosity. Additionally, it is common for hosts to pressure their guests to overeat as a part of hospitality. One student indicated that there are some hosts who insist on offering tea  to a person with diabetes. Hosts sometimes offer sweets, insisting that such a small portion will not hurt. The host may feel offended if the guest does not drink or eat what is offered, leading to many complications as a result.Cooking SkillsI never learned how to cook. I still live with my family so my mother or sister cooks for us all the time” (Fourth-year student).Another aspect students discussed was that males usually do not cook in the Saudi culture, females do. Thus, the majority of students have not learned to cook. If the students do not live with their parents, it is very common for them to eat out during that period. “Social NormsMost students, including myself, do not take breakfast from home, unlike western societies where students can bring their meals to the university with them. However, it is not accepted here in our society” (Fourth-year student).Some students talked about how they were discouraged from bringing their meals from home to the university. They said that other students might think a person is cheap if they bring their meal with them. “Physical activity was mandatory in high school every morning before classes start” (Second-year student). “I used to play football almost every day in high school, but now I’ve stopped” (Fourth-year student).Participants stated that most students reduced their physical activity after starting university. “How will the student concentrate during the lecture, he will be tired after exercising?” (Second-year student). In addition, some students thought that exercising with the air conditioner on can be harmful. “How do you exercise with the air conditioner is on? You definitely will get sick” (Third-year student).Students seemed to know about physical activity and its importance to health in general. However, some students had misconceptions about physical activity. They thought that exercising can make you mentally tired. “I don’t like to exercise” (Second-year student). “I am not motivated to exercise” (Third-year student). “Why should I bother to exercise?” (Second-year student).Some participants said that they do not exercise due to a lack of interest or enjoyment, as well as being tired or lazy. “We don’t have enough time to exercise; time controls us so we can’t exercise regularly” (Second-year student). Some students added that driving the long distance to their homes takes a lot of their time. “If you live far away, you arrive home feeling tired. You can barely find time to study and sleep” (Second-year student).Lack of time was a major issue that students talked about. They indicated that stressful schoolwork and exams are taking most of their time, making it difficult to exercise. “I have many responsibilities besides the university like taking care of my parents’ needs, buying groceries, and taking my siblings to schools” (Third-year student). Lack of positive social factors was an important aspect that the students discussed. “I won’t exercise alone. I would feel bored” (Second-year student). “You are more likely to play football if your friends play it regularly. However, you wouldn’t play if they don’t” (Fourth-year student). Students also mentioned that there is a lack of social activities. “If activities are available, all students will participate” (Third-year student).Students also talked about other external factors that consumed their time such as family responsibilities. “I haven’t seen any student using them” (Second-year student). They mentioned that some of these facilities are not always accessible . They pointed out that there was a shortage of equipment for exercising in these facilities. Most students did not support the idea of exercising and going to the lecture afterwards. “We came here to study and not to exercise” (Second-year student) “Society does not generally accept it” (Fourth-year student). They mentioned that the facilities lacked dressing rooms, lockers, and showers. “I don’t want to go to class after I sweat and smell bad” (Second-year student). “Usually if a student has some time, he will play table hockey, pool or table football. However, it is difficult to use a treadmill and avoid sweating before lectures” (Fourth-year student). Some students talked about alternative fitness centers, but most cannot afford their pricy subscriptions. In addition, a couple of students brought up bad weather conditions. “Heat, humid, and sometimes dust make it difficult to go outside for a walk” (Fourth-year student). Some students discussed dependence on cars and how it restricted their physical activity. “The environment is built for cars, nothing else” (Second-year student).The students discussed the on-campus facilities and how these were being neglected. “Students indicated that their sedentary behaviors had increased since enrolling in the university due to many factors related to the dependence on today’s technologies and rapid modernization.Students know sitting for a long time is bad for you, yet they still do it” (Fourth-year student).The majority of students were aware of sedentary behaviors and their negative effects on health. “We do have lectures that last up to three hours without breaks. We sit for a long time” (Second-year student). Dependence on passive transportation, mainly cars, was indicated by students as another reason for sitting a lot. Some students mentioned sitting in the car for a long time because they live in villages nearby. “I live in a very far place, so I drive about an hour to get here” (Second-year student).The students indicated that they had to spend a lot of time sitting for schoolwork purposes including lectures, studying, or computer use. “I used to play football with my friends outside. Now, we just meet online and play together for hours” (Second-year student). Many students stated that they like to watch TV. “After a long day at the university, I just prefer to rest at home and watch a movie or two” (Fourth-year student). “Binge watching” was common among students as well. “My problem is that I am addicted to Netflix. I can sit all day and watch my favorite series, one episode after another” (Third-year student). The students discussed smartphone use and its relation to sedentary behavior. “Many students including myself spend hours on the phone using social media apps, streaming videos, and video gaming” (Second-year student). Some students talked about khat consumption, which is part of Jazan’s culture. Khat is a type of drug that you chew. However, as it is officially illegal, it is usually consumed in small groups in a room, which means that the khat consumers just sit for many hours.Students talked about video games and how addictive they can be. “Sleep duration was commonly perceived as having decreased since attending the university. Many students did not have enough sleep according to the participants, because of stress, irregular schedules, schoolwork, exams, family responsibilities, and khat consumption. Other students  mentioned that due to being new in the city and not having any social engagement after school, they had more than enough sleep.Students had adequate information about sleep and its relation to overall health. They also indicated that adequate sleep can improve productivity and increase performance. Most students suggested that an adult should sleep about 7 to 9 hours at night.I am a night person. I like to stay up late and get things done. I usually function better at night” (Second-year student).Some students mentioned that they like to stay up late to complete various tasks or to gather with family and friends for fun. “It is impossible for me to sleep at night during finals. I prefer to stay up all night and study.” (Fourth-year student). “Students sleep less because they have many things to do like assignments, presentations, and projects. They can barely keep up” (Third-year student).Some students revealed that they tend to postpone schoolwork until the last minute. As a result, they become stressed due to lack of time, and they do not have much sleep. “There is a problem in the region, which is khat consumption. It makes you sit for hours without engaging in any physical activity. Also, it keeps you awake all night, so most consumers go to university without sleep. Khat is very popular among Jazan students” (Fourth-year student).Many students reported the use of khat and how socially accepted it is in their environment. “The purpose of this study was to investigate which factors impact weight change, dietary habits, physical activity, sedentary behaviors, and sleep behaviors in Saudi university students. To the best of our knowledge, this is the first focus group study to explore the potential determinants of these behaviors in the region. Results could be well-structured with Social Cognitive Theory, as personal, social, and environmental factors were discussed the most.Overall, students thought that the transition to college life was related to factors that lead to weight gain, such as unhealthy eating behaviors, low physical activity, high sedentary behaviors, and inadequate sleep. These findings are consistent with other qualitative research on determinants of weight-related behaviors among students carried out in the Western world .Environmental factors within the university were mentioned as important for all weight-related behaviors but sleep. According to the students, no healthy foods were offered at the campus site. Sport facilities at the campus were only open for very limited hours, and showers, lockers, and dressing rooms were lacking. Furthermore, lectures and studying forced them to be sedentary. Studies have shown that the availability of healthy food choices and sports facilities are linked to a healthier diet and more exercise ,9,24,25.Dietary habits and physical activity shared similar personal factors that impeded these behaviors such as lack of knowledge and time and stress. The students showed a clear lack of knowledge, motivation, and time when it comes to eating behaviors and physical activity. Some students thought that quality and quantity of food do not matter as long as the person exercises. Additionally, misconceptions such as that exercising leads to losing one’s concentration or that you fall ill when exercising with the air conditioner on were quite common. Many students agreed that they eat unhealthy food more frequently and exercise less during stressful periods such as exam weeks. They appeared to have poor time management during such times, which led them to being stressed and consequently making unhealthy choices. Lack of motivation and lack of positive social factors  were also seen as hindering both healthy dietary habits and physical activity. Most of these findings are in line with other studies carried out in other parts of the world ,7,8,9. WPrevious studies found similar findings related to prolonged sitting for study purposes and screen use ,26,27. CStudents do not spend enough hours asleep at night due to many factors such as enjoyment, stress, lack of time, and khat consumption. Staying up late is very common among students. Nightlife encourages students to stay up late as most restaurants and cafes are open until two in the morning. In addition, it is cooler at night, which can be a motivator for students to stay up late and enjoy the relief from the day’s intense heat.The findings of this study can support the development of health promotion interventions that target university students in regions that are comparable to the one studied here. Based on our findings, we would suggest an intervention that targets several levels at a time: the university level, the social level, and the individual level.A university environment that promotes and facilitates healthy food choices and physical activity seems to be key. Promoting a healthy food environment with a food system that ensures the availability and affordability of diverse, balanced, and healthy diets is crucial. The university could play a major role in creating such a supportive healthy food environment that enables students to adopt and maintain healthy dietary practices easily. Furthermore, if sport facilities on campus had showers, lockers, dressing rooms, and longer opening hours, they would be used more. The university campus infrastructure could be restructured to support students to become more active unintentionally by walking and cycling to classes.At the social level, student organizations could organize social activities that also have a physical activity and/or healthy food component, such as playing soccer or cooking courses for male students and eating a healthy meal together at a social gathering in the evening.At the individual level, students need to adopt the idea of a healthy active lifestyle through increasing knowledge and awareness in order to avoid misconceptions, along with increasing positive social influence and support. Strategies to enhance time management could be introduced to reduce stress, as this seems to be an important factor in the unhealthy lifestyle of students.Any intervention needs to consider these personal, social, and environmental factors in order to promote a healthy lifestyle in university students. “Health Promoting Universities” is an example of an initiative that aims to encourage universities to promote health and wellbeing through programs focusing on students, staff, and the wider community . TargetiOne of the limitations of this study is the sample population, which consisted only of male students and only of university students in one region. Therefore, our results cannot be generalized to the Saudi university population. To develop an evidence-based intervention for all students, comparable studies should be conducted among female students, and in other regions. Another limitation of our study is that the data are self-reported; participants may have given social desirable answers. A third limitation is that participants volunteered to be a part of the study. Therefore, students especially interested in health issues and more knowledgeable about health-related issues may have participated. However, as the results showed, the participants had several misconceptions about health-related issues. One strength of the study is that it provided depth and details on the factors that influence weight-related behaviors in their full breadth: unhealthy eating, physical activity, sedentary behavior, and sleep quality. A future study should investigate whether the factors that seem to be weight-related behaviors in the present study are also found in a quantitative study of a larger, representative student sample.The present study gave valuable insights into the reasons Saudi students have to perform or avoid weight-related behaviors. That part of our results was in line with those from other studies confirms that our participants wanted to discuss our topics in an open and cooperative way. Another part of the results suggested the importance of regional and culture-specific factors, adding to our knowledge, which can be used to develop regional and culture-sensitive health promotion interventions.The current study concludes that university students’ weight, dietary habits, physical activity, sedentary behaviors and sleep quality behaviors can be mainly influenced by personal, social, and environmental factors. University facilities including canteens and physical activity facilities should acknowledge their role in guiding healthy behaviors and be the first to engage in creating a healthy environment for students. It is of great importance to develop evidence-based studies that target these determinants on a large scale. Evidence-based health promotion initiatives that combat these weight-related behaviors can be planned based on the findings of such studies.


Physical activity is a multifactorial trait, determined by both individual and environmental characteristics, it seems relevant to understand the determinants related to youth guidelines accomplishment. The present study aimed to verify the differences between the Brazilian federative units regarding to the prevalence of youth physical activity guidelines accomplishment and to investigate the determinants related to the inter-individual differences in this accomplishment.Sample comes from the 2015 Brazilian National School Health Survey (PeNSE), comprising 99,570 adolescents , enrolled in 3039 schools. Adolescents reported the time they spend in moderate-to-vigorous physical activity daily, and they were categorized as active or inactive, if the guidelines were achieved, or not, respectively, and multilevel statistical analyses were used, including both child and school-level variables. Multilevel Binomial model was computed in the SuperMix software.The majority of the adolescents did not comply with the physical activity guidelines daily, where Bahian children complied the least, while those from Amazonas, Tocantins, and Mato Grosso do Sul complied the most. Boys , older adolescents , and those who spent more time in active travelling to/from school  complied more the physical activity guidelines. At the school level, adolescents from larger schools  tended to comply less with the guidelines.Significant differences between Brazilian federative units in youth daily physical activity guidelines compliance were observed, highlighting the role of individual but also environmental constraints in the Brazilian adolescents’ engagement in physical activity. In the last years, increases in physical inactivity have been pointed as one of the most relevant public health problems, especially among youth, given the health problems related to it such as non-communicable diseases . Taking Given that Brazilian states show a great diversity between them, regarding not only to cultural aspects but also regarding economic and social factors , these dGiven that, since physical activity is a multifactorial trait, determined by both individual and environmental characteristics, it seems relevant to understand the determinants related to youth guidelines accomplishment. Thus, the present study aims (1) to verify the differences between the Brazilian federative units regarding to the prevalence of youth physical activity guidelines accomplishment and (2) to investigate the determinants related to the inter-individual differences in this accomplishment.The sample of the present study comes from a cross-sectional study conducted by the Brazilian Institute of Geography and Statistics (IBGE) in association with the Ministry of Health. Data used is from the 2015 Brazilian National School Healthy Survey (PeNSE), an epidemiological study carried out with Brazilian school-children enrolled in both public and private schools, from the 26 states capitals and the Federal District, as well as from other municipalities which were grouped into 26 geographical strata  . Given Information regarding daily time spent in physical activity, as well as time spent in active commuting to/from school were self-reported via questionnaire , which wFurthermore, they were also asked to inform how many minutes per week they spent in active commuting to/from school, and the total weekly amount was used in the present study.Adolescents answered about the educational level of their mothers, ranging from “did not study” until “undergraduate or higher level”.Information about the school environment was obtained via questionnaire, answered by the school’s principals or his/her designee. From the set of available variables, those chosen from the study were “school size”, “the existence of gymnasium”, “the existence of playground area”, and “the existence of sports equipment”, based on previous studies where these variables were used as possible predictors of physical activity in school-children , 15. AllDescriptive statistics are presented as mean and standard deviation, or frequencies, which were computed in the SPSS 24. Since the dependent variable  is a count ranged from 0 to 7, and the hierarchical structure of the data, a multilevel Binomial model was used, computed in the SuperMix v.1 software, and using a full maximum likelihood approach. The modelling was performed in three steps: Model 1, including only the federative units. To observe federative units differences in physical activity compliance days, federative units were dummy coded, where the Bahia state was the site reference (since it showed the lowest percentage of children classified as active); Model 2, adding the child-level predictors - sex (girls were the reference), age (mean centred), time spent in commuting transport to/from school (mean centred), and maternal education level ; and Model 3, including the school-level predictors - “school size”, “the existence of gymnasium”, “the existence of playground area”, and “the existence of sports equipment”, where all the school-level predictors were dichotomized . Significance level was set at 5%.Descriptive statistics for child and school-level variables are provided in Tables Regarding the school context, it was observed that the majority of them have more than 500 students enrolled. Taking into account the other school context variables, a wide difference was observed across the states, but some similarities were seen within geographical regions.Figure Multilevel modelling results are presented in Table p < 0.001). It was possible to observe that all the variables included in the model were significant in the explanation of children differences in physical activity compliance rate. Children from Sergipe differ from those from Bahia, complying more the guidelines (OR = 1.123); on the other hand, those from Rio de Janeiro, Rio Grande do Sul, and Pará did not differ from their Bahian peers. On average, boys complied more than girls (OR = 2.306), as well as older children (OR = 1.044), and those who spent more time in active travelling/week to/from school (OR = 1.001) complied more than their youngest and those who spent less time in active travelling to school peers, respectively. In addition, increasing mother educational level, increased the odds of children compliance of the physical activity guidelines.In Model 2, child variables were included, and it fits the data significantly better than Model 1 . Among states, results were similar from those observed in model 2. The child-level variables remained significant, with small changes, meaning that their interpretation did not differ to that from the previous model. Further, from the school context variables, only school size showed to be a significant parameter for children compliance guidelines, where children enrolled in schools with more than 500 students were less likely to comply with the physical activity guidelines (OR = 0.957).In the Model 3, the school-variables were included, namely school size, and the existence of gymnasium, playground area, and sports equipment. This last model fits the data better than Model 2 . Notwithstanding data from the present study comes from one single country, it is observed a range variability in children physical activity compliance between states; although in the present study it was not explored states characteristics that could explain these differences, it is possible that these results may be related to differences in socioeconomic, cultural, and political characteristics , that maResults of the multilevel analysis revealed differences in physical activity compliance rate across states. The Bahia site was the reference (its adolescents had the lowest compliance rate), and the States-Model (Model 1) revealed that within Northeast region, only adolescents from the Rio Grande do Norte state complied significantly more than Bahian youth, with no other significant difference observed among others Northeastern states. It is well knowing that physical activity is influenced by socio-environmental aspects , such asThere is a consensus about the influence of biological and demographic factors on physical activity levels, which was explored in the model 2. Regarding to child-level variables explored in the present study, all of them showed to be significant predictors of youth physical activity compliance rate. Older youth complied more the guidelines than their youngest peers, and this result differs from some of those previous reported, where authors suggest that  both biological (such as hormones release) and environmental characteristics  can lead to the reduction of physical activity over time , 23. RegFurther, it is known that parents/legal guardians socioeconomic status may play a relevant role in children's physical activity involvement  and lega2) where these activities can be performed by students [Since children spend a relevant part of their awake time at school, this environment seems to be of relevance for students' physical activity, since most of their active and healthy habits can be created and/or maintained in it . For exastudents , 37.This study has some limitations, namely (1) the use of questionnaire to collect information regarding youth physical activity/active commuting, which can be prone to error and/or bias in information; however, epidemiological studies have used this approach to data collection, meaning that this is a usual strategy used when large number of subjects are sampled, given the positive cost-effectiveness relationship; (2) the limited number of school predictors used could not be enough to better understand the role of school context on Brazilian youth physical activity, but the variables used were selected according to previous studies where the role of school on scholars’ physical activity was investigated; furthermore, previous studies have also reported a set of school variables that were not significant in the explanation of differences in youth physical activity level; 3) the model's goodness was assessed using the cross-validation procedure and, based on it, the results found in the present study cannot be generalized for the entirely Brazilian school-age adolescents. But the study has some strengths, such as the use of a large sample size, with youth from all the Brazilian federative units, with different socioeconomic and cultural characteristics; the use of multilevel analysis, allowing to understand the complex issue of individual- and school-level variables and how they can influence on youth physical activities practice.It was possible to observe that most of Brazilian schoolchildren did not comply with the daily physical activity guidelines, with a large variance across the states, where Bahian children were those who complied the least, while their peers from Amazonas were those who complied the most. Boys, older youth, and those who spent more time in active travelling per week to/from school were more likely to achieve the physical active guidelines, as well as it was also observed a significant role of maternal education level on it. Moreover, from the set of school variables, only school size (namely the number of students enrolled in school) was a significant predictor to physical activity achievement. The results highlight the role of individual and environmental characteristics (states and school) in children's daily physical activity compliance, and especially in the Brazilian context it shows that states constraints play a relevant role in these differences, meaning that policies should be thought taking into account these environmental discrepancies.