N = 1105) the Internet use/abuse, the adolescents' attachment to parents and peers, and their psychological profiles. Hierarchical regression analyses were conducted to verify the influence of parental and peer attachment on Internet use/abuse, considering the moderating effect of adolescents' psychopathological risk. Results showed that adolescents' attachment to parents had a significant effect on Internet use. Adolescents' psychopathological risk had a moderating effect on the relationship between attachment to mothers and Internet use. Our study shows that further research is needed, taking into account both individual and family variables.Adolescents are the main users of new technologies and their main purpose of use is social interaction. Although new technologies are useful to teenagers, in addressing their developmental tasks, recent studies have shown that they may be an obstacle in their growth. Research shows that teenagers with Internet addiction experience lower quality in their relationships with parents and more individual difficulties. However, limited research is available on the role played by adolescents' attachment to parents and peers, considering their psychological profiles. We evaluated in a large community sample of adolescents ( During the last decade, there has been an enormous development and diffusion of new forms of Internet-information and communication technology, such as social media, personal computer, mobile or cellular phone, and other devices . AdolescDuring adolescence numerous changes occur, abilities functional to self-regulation are still relatively immature : recent Beyond the numerous advantages offered by the new forms of technology, recent research has evidenced that adolescent population had a higher risk to develop Internet problematic behavior, a condition defined as Internet addiction (IA) . HoweverAmong adolescent and young adult population, epidemiological research reported a prevalence ranging from 1% to 18% , 28, 29,However, although the literature has been increasingly interested in the possible impact of Internet use/abuse on adolescent's development, limited research is available on the role played by adolescents' quality of attachment to parents and peers, considering their psychological profiles.In accordance with the Developmental Psychopathology , clinicaDuring adolescence, there is an increased need for autonomy and independence from parents. Consequently, in these different phases adolescents have to renegotiate their relationships with them , 35 and Attachment theory  offers aIn particular, it has been evidenced that low attachment to parents is associated with higher time spent on Internet , 45 and Adolescents that feel that their relationships with parents are cold, not supportive, and emotionally unavailable may excessively use Internet to search for alternative social support, especially by peers , 54. IndAs regards the role played by psychological functioning, several studies, rooted in genetic and epigenetic research, have underlined that adolescents that excessively use Internet often had a wide range of psychosocial correlations, such as impulsivity , shynessdifferences in the use/abuse of Internet, psychopathological risk, and adolescent's attachment on the basis of sex and age;the influence of attachment to parents and peers on use/abuse of Internet, considering the effect of adolescents' psychological profiles.On the basis of previous literature, which has underlined the correlations between the adolescents' primary relationships, their psychological difficulties, and the IA, we aim to study in a large community sample the Internet use/abuse. Indeed, to the best of our knowledge, no other studies have specifically investigated adolescents' attachment to parents and peers and its influence on adolescents' Internet use/abuse, considering their psychological profiles. Therefore, the present study aimed to investigate in a large community sample early adolescence, from 12 to 14 years ; middle adolescence, from 15 to 17 years ; and late adolescence, from 17 to 20 years .Over a period of one year, 1105 adolescents (43.6% boys and 56.4% girls) from 12 to 20 years  were recruited for this study, through the collaboration of high schools of center-south of Italy. Sample was divided into three age groups on the basis of scientific literature : early aThis study was approved before its start by the Ethical Committee of the Department of Dynamic and Clinical Psychology at Sapienza University of Rome, in accordance with the Declaration of Helsinki. All adolescents and their parents signed informant consent, in which the study was illustrated in detail.N = 926), while 14.8% (N = 163) are separated/divorced.Most of the adolescents recruited for the study lived in families (98.6%). 83.8% of parents are married or cohabiting  and accepted to participate in the study were administered the following self-reporting instruments. The order of administration was randomly decided. Symptom Checklist-90-Revised , indicating the total subjective distress.TheCL-90-R; ) is a muα coefficient, 0.70–0.96) with a clinical cut-off score ≥ 1 in GSI indicating psychopathological risk [Prunas et al.  demonstrcal risk . Shorter PROMIS Questionnaire  is consre  is a se Studies conducted by the authors show that adolescents who report safety concerns about parents and peers have even less conflict with parents, more satisfaction in life, more self-esteem , and pooThe Italian validation  showed aA preliminary screening of the data showed few data missing for each instrument (2% for each instrument). Missing data were corrected using multiple imputation in SPSS software (version 24.0).To examine the adolescents' use/abuse of Internet, their attachment with parents and peers, and their psychological profiles, we carried out multivariate analyses of variances (MANOVAs), considering the effects of sex and age group. We considered as dependent variables the adolescents' SPQ total score, the IPPA subscales and total scores, the SCL-90-R subscales and total score, while we considered sex and age group as the independent variables. In all MANOVAs, univariate analyses were then conducted on significant effects, and the Bonferroni's test was used for contrasts.After verifying the presence of correlations between variables, hierarchical regression analyses were conducted to verify the influence of parental and peer attachment on Internet use/abuse, considering the moderating effect of adolescents' psychopathological risk. Specifically, the IPPA instrument's subscales were used as independent variables, adolescents' SCL-90-R Global Severity Index as moderator variable, and the SPQ total score as a dependent variable. Moderation analysis was conducted utilizing the PROCESS macro for SPSS . All anaF = 6.64; p < .05). Furthermore, early adolescents showed higher scores than late adolescents . No significant differences in scores were found on the basis of sex ∗ age groups . We carried out univariate analysis of variance (ANOVA) to verify differences in Internet use/abuse in adolescence, on the basis of sex and age group. Results show that girls had higher scores than boys  to verify differences in adolescents' attachment to parents and peers on the basis of sex and age groups.F = 21.24; p < .001). Univariate analyses were conducted on significant effects, and the Bonferroni's test was used for contrasts. Mean and standard deviations of adolescents' attachment to mother, father, and peers on the basis of sex and age group are illustrated in Results show the presence of significant differences on the basis of sex , mother alienation , mother communication , peers communication , and peers trust .Results of univariate analyses show that girls had higher scores than boys on the scales father alienation  to verify differences in adolescents' psychological profiles on the basis of sex and age groups.F = 17.28; p < .001) and age group .Results show the presence of significant differences on the basis of sex , depression , hostility , paranoid ideation , and Global Severity Index . Bonferroni post hoc test showed that late adolescents had higher scores than early adolescents on SCL-90-R subscales: obsession-compulsivity (p < .01), depression (p < .01), paranoid ideation (p < .01), and Global Severity Index (p < .05). Furthermore, late adolescents showed higher scores than other groups on the subscale hostility (p < .05). Regarding the effect of age groups, results show differences in SCL-90-R subscales: obsession-compulsivity  and fathers  but not by adolescents' attachment to peers (p > .05).At Step 1, analysis shows that Internet use/abuse was predicted by adolescents' attachment to mothers , but this moderating effect was not found in the influence of attachment to father and peer on Internet use/abuse (p > .05).At Step 2, results show that adolescents' Global Severity Index moderated the influence of attachment to mother on Internet use/abuse  = 69.66, R2Δ = .16, p < .001). Conditioned at 1 standard deviation below the mean on Global Severity Index, attachment was inversely related to use/abuse of Internet , and when conditioned at 1 standard deviation above the mean on GSI, attachment was inversely related to use/abuse of Internet . In fact, test of highest order unconditional interaction showed R2chng = .0042; F = 5.53; p = .019.Results show an attachment to mother × SCL-90-R Global Severity Index interaction effect in predicting use/abuse of Internet  to verify differences between boys and girls in different development stages in Internet use/abuse. Results showed that girls had higher levels of Internet use/abuse than boys. International scientific literature in this field is contrasting. Although previous researches have evidenced a higher risk of Internet overuse among boys , 80, othFurthermore, analysis showed that early adolescents show higher scores than late adolescents on Internet use/abuse. Previous research has reported mixed findings: some studies have underlined a significant higher incidence of Internet use/abuse during middle adolescence  or late Moreover, analysis showed that girls had higher levels of communication with mothers than boys, but also higher levels of alienation with fathers and mothers. This is consistent with previous studies that have reported a perception of higher quality of communication with mothers  and highRegarding peers, girls showed more trust and communication. This is in line with previous studies that have reported a higher level of peer attachment among teenage girls , 91. SomInteresting data have emerged as regards psychopathological profiles. In fact, analysis showed that girls had more maladaptive psychological profiles than boys on all areas. Recent studies have evidenced that girls reported higher psychopathological symptoms than boys, especially in internalizing area , but ourAs regards developmental stage, results showed that late adolescents had higher levels of depression, obsession-compulsivity, paranoid ideation, and hostility than early adolescents and confirm previous studies that have underlined an increase in psychopathological difficulties during the development .International studies have widely evidenced that during adolescence emotional-behavioral functioning is hyperactivated  and manyOn the basis of these theoretical and empirical premises and in order to be able to assess the possible influence of attachment to parents and peers on the use and abuse of Internet, hierarchical regression analyses were conducted, assessing the moderating effect of the psychopathological risk.R2chng = .0042). In fact, results showed that a higher attachment of adolescents to the mother predicted less Internet use/abuse, but this predictive effect is reduced by the presence of adolescents' psychopathological risk.Analysis showed that adolescents' attachment to parents (but not to peers) influenced Internet use/abuse. Furthermore, moderation analysis suggested that adolescents' psychopathological risk had a moderating effect on the relationship between attachment to mothers and the use of Internet. Although this result is significant, the effect size is not great (Overall, our results evidenced the crucial role played by attachment on adolescent's Internet use. These findings suggest that unpleasant feelings of isolation, anger, or detachment experienced in attachment relationships with parents may predispose adolescents to cope with these emotions through an excessive use of Internet, in order to avoid and/or reduce the distress resulting from adverse attachment experiences , 45.This study has some limitations. In fact, some individual variables of the adolescent were not investigated, such as traumatic events that may have been experienced by young people , 101 andIn light of the results, we believe that further studies are important to investigate more individual variables of teenagers, in order to allow greater understanding, so that appropriate prevention and treatment programs may be implemented.


To compare regular physical activity among adolescents living with human immunodeficiency virus (HIV) with their healthy peers, and to evaluate the relationship with anthropometric indicators of body fat.  This was a cross-sectional study which investigated two groups: 57 adolescents (10-15 years of age) living with HIV, and 54 apparently healthy adolescents matched for sex and age. Physical activity was evaluated using a questionnaire and anthropometric measurements were performed. The groups were compared in terms of physical activity, and the linear and partial correlations (adjusted for age and sex) between physical activity and the anthropometric indicators were tested. versus 2.14; p<0.001), but participated more frequently in physical education activities. Soccer and walking were the physical activities most frequently reported by adolescents of the two groups. No correlation was observed between total physical activity score and anthropometric indicators of body fat when adjusted for sex and age. Female gender (β=21.51), months of exposure to antiretroviral therapy (β=1.26), and socioeconomic classes B and C  explained 33% of the sum of skinfolds in adolescents living with HIV .  Adolescents living with HIV had a lower total activity score than their healthy peers (1.73  Adolescents living with HIV have lower physical activity scores compared with their healthy peers, but physical education was found to be an opportunity to increase physical activity. Physical activity brings many health benefits and prevents, primarily and secondarily, degenerative complications of various diseases.In adults with HIV, a meta-analysis found that aerobic, resistance or combined exercise, reduces body fat, increases lean body mass, as well as improves strength, aerobic fitness, symptoms of depression, and quality of life.,,,Children and adolescents with chronic conditions often have restrictions on participation in physical activity and sports owing to actual and perceived limitations.The aims of this study were:to compare the physical activity among adolescents living with HIV and their healthy peers;to investigate the relationship between physical activity and anthropometric indicators of body fat in adolescents living with HIV, and making adjustments for possible confounding factors.Hospital Infantil Joana de Gusmão (HIJG) in Florianopolis, Santa Catarina, Brazil. Inclusion criteria were:Observational and cross-sectional study including a control group for comparison, which investigated 57 adolescents of both sexes, aged 10-15 years, living with HIV acquired by vertical transmission, and in clinical follow-up at Presenting HIV infection by vertical transmission in medical records.+T cells, CD8+T cells, viral load, exposed or not to ART, type and duration of ART).Presenting clinical and laboratory evidence in the medical records ,® , with a capacity of up to 150 kg and resolution of 100 g. Height was measured using a stadiometer Sanny® , with resolution of 0.1 cm. Body mass index (BMI) was calculated based on these measurements. Triceps, subscapular, abdominal, and calf skinfold thickness and perimeters of the relaxed arm and waist were measured with a Cescorf adipometer  and anthropometric tape Sanny®, respectively. All measurements were obtained by raters who were calibrated and certified by ISAK.The body weight, height, skinfold thickness, and body circumference measurements were obtained. For all the children, the procedures of the International Society for the Advancement of Kinanthropometry (ISAK) were followed. Body mass was measured with a digital scale TanitaAssociação Brasileira de Empresas de Pesquisa.The sociodemographic information on participants’ age, gender, and skin color, as well as family income and education of the parents or others responsible for the participant was collected in an interview. The economic level was determined according to the t-test for independent samples was used to compare physical activity and body fat between HIV+ and control groups. Pearson product-moment correlation and Spearman’s rank correlation were used to test the relationship between the score of physical activity and anthropometric indicators of body fat, for normal and asymmetric data, respectively. The partial correlation was tested with a control on the effect of sex and age. The magnitude of correlation between variables was interpreted according to the strength of the relationship . For all analyses, we used the software STATA, version 11.0, establishing a value of p≤0.05.Data were processed in Epidata program, version 3.1. Descriptive statistics were used for data analysis . The Kolmogorv-Smirnov test and histograms were used to verify data normality. Student’s Universidade Federal de Santa Catarina (CAAE: 34505314.7.0000.0121). The legal guardians signed an informed consent form to participate in the research. This study was in compliance with the Guidelines and Norms Regulating Research Involving Human Subjects of the National Health Council Resolution 466/12.This study was approved by the Ethics Committee in Research with Human Beings (CEPSH) of the + (n=57) and control (n=54) groups. In HIV+ group, most of the students were female (57.1%) and had white skin (29.8%), low income (56.1%), and low educational level . In the control group, 51.9% of participants were female, predominantly white (57.4%), had low income (44.4%), and low educational level (59.3%). There were no significant differences in socio-demographic characteristics between the groups. This study included 111 adolescents, aged 10-15 years, distributed in HIVWith regard to the clinical status of adolescents living with HIV, all adolescents aged below 13 years were in early stages of the disease, in asymptomatic or mild stage. For adolescents aged over 13 years, three had severe immunosuppression. Regarding the viral load, 31 (54.4%) adolescents had undetectable levels; 26 (45.6%) adolescents had detectable levels, six (10.5%) adolescents had viral load above 10 thousand copies, and two (3.5%) adolescents had viral load above 100 thousand copies. Other clinical and laboratory data are shown in p<0.001), although there is no difference in the activities performed during the week and on weekends. The prevalence of insufficiently active participants was 96.5% (n=55) for the case group, and 92.6% (n=50) for the control group. On an average, one-fourths of the sample does not perform any activity on weekends. On the other hand, more than half of the participants reported they always participate in physical education classes, and the greater proportion was among adolescents living with HIV, as compared to the control group (p<0.001). During school recess, both the groups were poorly engaged in physical activities, and 30% of them remained seated . Among the participants, 28% did not engage in physical activity on any day after the school.p<0.001), months of exposure to ART , and economic classes “B” and “C”  explained 33% of the variation in body fat in adolescents living with HIV . Years of exposure to ART showed an inverse relationship with the subscapular skinfold thickness  and a positive relationship with body mass , height , and arm circumference . There were no differences in the triceps, subscapular, abdominal, and calf skinfold thickness as compared with HIV+ adolescents who used ART with protease inhibitors (PI) (n=36), ART without PI (n = 13), and did not use ART (n=8) (data not shown).In the bivariate analysis, there was an inverse relationship between the overall score of physical activity and body mass, abdominal skinfold, and the sum of skinfolds in adolescents living with HIV. However, when adjusted for the effect of sex and age, the correlations did not remain significant . In addi+ group is poor (<0.40) and disappears when adjusted for sex, age, and exposure to ART. The sex, the time of exposure to ART, and economic level explained 33% of the sum of skinfolds in HIV+ group.The main finding of this study was to observe that adolescents living with HIV showed lower scores of physical activity when compared with those of the control group. However, they were more active in physical education classes. Participants of both groups were most often engaged in soccer and walking. The bivariate analysis showed that the relationship between physical activity and body fat in HIV+ adults, regular physical activity may be a tool to improve body composition.There is consensus in the literature that moderate to vigorous physical activity in healthy children and adolescents, performed for at least 60 minutes daily, brings benefits to cardiovascular health, decreases body fat, increases flexibility and muscle strength, in addition to bringing other psychosocial benefits.+ girls (aged 5-9 years), less time spent in vigorous physical activity and a lower participation in school physical education compared with healthy girls were observed.Lower scores of regular physical activity among adolescents living with HIV reinforce what was observed by the Specialized Care Service, which found a prevalence of 71.7% of adolescents who did not meet the recommendations on the practice of physical exercise.+ adolescents were soccer, volleyball, and cycling; however, the participants belonged to a broader age range.In both groups, girls reported walking, running, and/or jogging, and boys played soccer. Similar to our study, there are reports that soccer and dance are the activities most commonly performed among boys and girls.Although the lowest total score of physical activity has been found in this study, adolescents living with HIV showed increased participation in physical education classes. This is a mandatory curriculum subject regulated by Law No. 9,394, of 12/20/1996, which at least can partially contribute to children and adolescents to become more active, as they spend much of their day at school.Although several studies have shown an inverse relationship between regular physical activity and body fat in healthy adolescents,+ adolescents experience by the infection and exposure to ART. Adolescents living with HIV are generally shorter and have less body mass, as well as enter puberty late, when compared with their apparently healthy peers.Our hypothesis for the lack of correlation between physical activity and body fat indicators is based primarily in the process of growth and development of adipose tissue that HIV,+ group were infected via mother-to-child transmission, which also characterizes a long exposure to the virus. Therefore, strategies to minimize the adverse effects of long exposure to ART should be sought. These complications can decrease the quality of life of this population and interfere with regular physical activity,More than half of these adolescents have undetectable viral load, which reveal the adequate clinical status of patients and the efficacy of drugs, which consequently can provide better quality of life.Limitations of this study include the cross-sectional design, which encompasses the inability to establish cause and effect, the subjective measure of physical activity by questionnaire and indirect assessment of body fat. The strengths include selecting the sample from a referral hospital in the treatment of pediatric HIV and having a control group matched for sex and age.We concluded that adolescents with HIV have lower scores of regular physical activity when compared with their healthy peers, although they have greater participation in physical education classes at school. The school environment can be a privileged and even more favorable space to promote physical activity among this population. Longitudinal studies are needed to confirm whether low levels of regular physical activity persist until adulthood. Sex, exposure to ART, and economic level explain a third of the sum of skinfolds in adolescents living with HIV. Although physical activity was not related to body fat indicators, studies with objective measures, which focus on metabolic health parameters that precede changes in body composition, are necessary.


Educational Research Review, 18, 46–57), which indicated a significant effect in favor of the groups playing chess. However, the meta-analysis also showed that most of the reviewed studies used a poor experimental design . We ran two experiments that used a three-group design including both an active and a passive control group, with a focus on mathematical ability. In the first experiment (N = 233), a group of third and fourth graders was taught chess for 25 hours and tested on mathematical problem-solving tasks. Participants also filled in a questionnaire assessing their meta-cognitive ability for mathematics problems. The group playing chess was compared to an active control group (playing checkers) and a passive control group. The three groups showed no statistically significant difference in mathematical problem-solving or metacognitive abilities in the posttest. The second experiment (N = 52) broadly used the same design, but the Oriental game of Go replaced checkers in the active control group. While the chess-treated group and the passive control group slightly outperformed the active control group with mathematical problem solving, the differences were not statistically significant. No differences were found with respect to metacognitive ability. These results suggest that the effects (if any) of chess instruction, when rigorously tested, are modest and that such interventions should not replace the traditional curriculum in mathematics.It has been proposed that playing chess enables children to improve their ability in mathematics. These claims have been recently evaluated in a meta-analysis (Sala & Gobet,  Students’ poor achievement in mathematics has been the subject of debate both in the United States , abilities that then transfer to other domains, and therefore benefits a wide set of non-chess-related skills  domains. It is customary to distinguish between near transfer, where transfer of learning occurs between tightly related domains  and far transfer, where the source and target domains are only loosely related. The presumed enhancement of mathematical ability from chess instruction is a clear example of far transfer.It has been proposed that transfer is a function of the degree to which two (or more) domains share common features  do not provide any general cognitive benefit or improvement in academic achievement. Reviewing the experiments where the effects of chess instruction have been experimentally studied suggests that chess is no exception.Thus, the hypothesis according to which one can improve one’s achievement in a wide set of fields by engaging in cognitively demanding activities is not supported in most areas. In fact, the abovementioned examples of music training and WM training suggest that those activities  engaging in one year of chess instruction (ranging from 25 to 30 hours) were compared to a passive control group of peers . The classes were randomly assigned to one of the two conditions. Pretest measures consisted of Key Stage 1 public examinations covering mathematics, science, and literacy. Posttest measures, which were obtained 1 year after the end of the treatment, consisted of Key Stage 2 public examinations in the same fields. No difference was found between the two groups in any of the measures. While some aspects of the design could have been improved  course, or regular school activities. The pupils were pre- and posttested on the same tests of mathematical ability and metacognitive ability as in the first experiment.SD = 0.67 years). Parental consent was asked and obtained for all the participants.A total of 233 third and fourth graders from eight Italian schools took part in this experiment only. The mean age was 8.50 years . The items used were all from the IEA-TIMSS international survey among fourth graders , which attended 25 hours of chess lessons during school hours,N = 82), which attended 25 hours of checkers lessons during school hours, along with regular school activities. Finally, the passive control group consisted of four classes , which attended regular school activities only.A convenience assignment to the three conditions was used. The group playing chess was compared to an active control group (playing checkers) and a passive control group (doing regular school activities). The experimental group consisted of three classes  did not introduce any mathematics-related topics, unless these were part of the games .F = 58.14, p < .001, and age, F = 4.22, p = .041, but no significant effect of group, F = 0.39, p = .679. The descriptive statistics are summarized in Table A univariate analysis of covariance (ANCOVA) was used to evaluate the role of group (independent variable), mathematics pretest scores (covariate), and age (covariate), in affecting mathematics postintervention scores (dependent variable). The results showed a significant effect of pretest scores, F, 228 = 5F = 82.50, p < .001, and age, F = 3.97, p = .047, but no significant effect of group, F = 0.62, p = .541. The descriptive statistics are summarized in Table The same analysis (ANCOVA) was used to analyze the results in meta-cognitive ability. The results showed a significant effect of pretest scores, F1, 28 = 82.5The results showed no significant differences between the three groups in mathematical ability or metacognitive ability.n = 15) originally dedicated to mathematics and sciences to directly compare the two games with the traditional methods of teaching mathematics and mathematics-related disciplines.The second experimentSD = 0.32 years). Parental consent was asked and obtained for all the participants.Fifty-two fourth graders in three classes of a primary school in Italy took part in this experiment. The mean age of the participants was 9.32 years . The second class attended regular school activities only (passive control group). Finally, the third class attended 15 hours of Go lessons during school hours, along with regular school activities (active control/placebo group).Importantly, the two interventions—that is, chess and Go courses—substituted part of the hours originally devoted to mathematics and sciences. This way, we could compare the effectiveness of chess (and Go) instruction with the traditional didactics of teaching mathematics and mathematics-related disciplines, such as sciences. Like in Experiment F = 1.03, p = .365. A univariate analysis of covariance (ANCOVA) was used to evaluate the role of group (independent variable) and mathematics pretest scores (covariate) in affecting mathematics postintervention scores (dependent variable). The results showed a significant effect of the covariate, F = 21.83, p < .001, and a significant effect of group, F = 3.37, p = .043. The pairwise comparisons showed that the control group outperformed the Go group (p = .017), the chess group marginally outperformed the Go group (p = .088), whereas no significant difference was found between the control and the chess group (p = .487). A more conservative post hoc analysis (Bonferroni correction) showed only a marginal difference between the control group and the Go group (p = .052). No other significant difference was found. The descriptive statistics are summarized in Table No significant differences between the three groups were found in the pre-test scores, F = 0.49, p = .617. A univariate analysis of covariance (ANCOVA) was used to evaluate the role of group (independent variable) and metacognition pretest scores (covariate) in affecting metacognition postintervention scores (dependent variable). The results showed a significant effect of the covariate, F = 47.81, p < .001, and no significant effect of group, F = 0.37, p = .694. The pairwise comparisons showed no differences between the three groups. The descriptive statistics are summarized in Table No significant differences between the three groups were found in the pretest scores, The effects of chess instruction on mathematical problem-solving ability were minimal. Children seemed to benefit more from the traditional didactics than from chess and Go instruction. Regarding metacognitive skills, children did not seem to benefit from any advantage from the 15-hour chess course. In fact, the participants performed equally across the three groups, suggesting that metacognition does not represent the cognitive link between chess instruction and mathematical ability.The results of the two studies do not support the hypothesis according to which chess instruction benefits pupils’ mathematical ability. The effects of chess, if any, appear to be minimal and certainly too limited to provide any educational advantage over the traditional instructional methods. Thus, chess instruction seems to align with the results obtained in the fields of music instruction and WM training. In a broader perspective, our findings are in line with Thorndike and Woodworth’s  common eGiven the small number of studies controlling for placebo effects, it is imperative to replicate and extend the experiments reported in the present article. Compared to the design we adopted, examples of possible ameliorations include full random assignment to the groups, measures of other cognitive constructs , and the manipulation of the duration of the chess interventions.In addition, an interesting way to make chess instruction more effective could be to make links between mathematics and chess explicit. Possible examples comprise introducing the Cartesian graph to pupils with the chess board and illustrating the concept of block distance—as opposed to distance in Euclidean space—with the movement of the King see Fig. . The incBeyond chess, the results of the research on chess instruction have profound implications for our understanding of learning and transfer of skill. There is a stark contrast between the enthusiasm displayed by the chess community and the sobering results from research on transfer and expertise: While the former heralds the positive benefits of chess instruction, the latter consistently report data speaking against the occurrence of far transfer. When critically evaluated, the literature on chess instruction is consistent with other experimental studies on transfer, indicating that far transfer is very unlikely. The results of the two experiments presented in this paper are consistent with these conclusions.Extrapolating from the research on chess and activities such as music and video-game playing, it is likely that the same difficulties in far transfer will be found with other kinds of games and play. To make the use of didactical games more effective, and given the difficulty of far transfer to occur, teachers and researchers should seriously consider the possibility of making explicit the link between playing games and the mathematical abilities the game is supposed to foster. Even so, it is worth reminding ourselves of French sociologist Roger Caillois’s  discussi


The short-term outcomes of laparoscopic-assisted surgery for colorectal cancer (LAC) have not been fully evaluated in elderly patients. The aim of this study was to compare the short term surgical outcomes of LAC between the patients older than 75 years and those with non-elderly patients.This retrospective multi-institutional study selected patients who underwent LAC between April 2013 and March 2014 at Yokohama City University Hospital and its related general hospitals. The patients were categorized into two groups: elderly patients (>75 years of age: group A) and non-elderly patients (<75 years of age: group B). Surgical outcomes and post operative complications were compared between the two groups.P = 0.750), median operation time , median blood loss . The differences were not significantly different in the surgical outcomes. The incidences of > grade 2 post operative surgical complications were similar between two groups . No mortality was observed in this study. The length of postoperative hospital stay was also similar .A total of 237 patients were evaluated in the present study. Eighty-four patients were classified into group A, and 153 into group B. Preoperative clinicopathological outcomes demonstrated no significant differences except for the ASA score. When comparing the surgical outcomes between group A and group B, the rate of conversion to open procedure (3.6% vs 5.2%, The present study suggested that LAC is safe and feasible, regardless of the age of the patient, especially for elderly patients who may be candidates for colon cancer surgery. Every year, more than 1.36 million people were diagnosed as colorectal cancer (CRC) world-wide, and CRC is the third most frequent cancer-related cause of death . CompletThe use of laparoscopic-assisted surgery for CRC (LAC) was first described by Redwine and Schlinkert in 1991 , 4. SincOn the other hands, the previous randomized studies excluded the patients over the age of 75 , 16 or iThe aim of this study was to compare the short term surgical outcomes of LAC and evaluate the safety and feasibility of LAC and compared them with non-elderly patients using multi institute data.This is retrospective multi-institutional study. Patient’s record was retrieved from the collected database of Yokohama City University, Department of surgery and its affiliated institutions between March 2013 and April 2014. The inclusion criteria were as follows; (i) histologically proven colorectal cancer, (ii) the patients over 20 years old, (iii) received laparoscopic surgery with lymph node dissection for colorectal cancer as primary treatment. The patients were categorized into two groups: elderly patients (>75 years of age: group A) and non-elderly patients (<75 years of age: group B).In principle, LAC was performed by 5 ports method under general and epidural anesthesia. Functional end to end anastomosis (FEEA) was performed for right-sided colectomy, and double stapling technique (DST) was performed for left-sided colectomy and rectum anterior resection. The number and position of intra-abdominal drainage tubes were determined by each surgeon. Pathological staging was carried out according to the UICC classification. The appropriate length of resection and the levels of lymph node dissection were generally determined by the Japanese Society for Cancer of the Colon and Rectum (JSCCR) Guidelines 2010 . MoreoveThe grade 2–5 postoperative complications  was used for all statistical analyses. R-category and extent of dissection were determined by the Japanese Classification of Colorectal Carcinoma 8th [The values are expressed as the median and range. The statistical analyses were performed using the chi-square test or the Wilcoxon signed-rank test. A noma 8th .The study was approved by the each Institutional Review Board of each hospital.p < 0.001 and p = 0.058, respectively). On the other hands, similar values were observed in body mass index and preoperative laboratory data findings.A total of 237 patients underwent LAC between 2013 and 2014 at nine institutions. Eighty-four patients were classified into group A, and 153 into group B. The background of the patients is summarized Table P = 0.750, one patient was bleeding and two were technical difficulties for securing a field of view over surgical sites in the elderly patients, while three patients were bleeding, one was technical difficulty, and others were metastasis or suspected direct invasion to other organ site in the non-elderly patients), median operation time , median blood loss . The differences were not significantly different in the surgical outcomes. Moreover, there were 12 patients having a stoma in non-elderly patients and 4 patients having a stoma in elderly patients. There was no statically difference between two groups. On the other hands, the rate of D3 Lymph node dissection was higher in group B . Pathologically, there are no statistically significant differences in T classification, N classification and UICC pathological Stage of the two groups.The operative details and pathological data were shown in Table p = 0.587). No mortality was observed in this study. The median Length of postoperative hospital stay is almost the same in the two groups (10 days (6–51) vs. 10 days (5–62)).Postoperative outcomes and its details were shown in Table In concerning the details of complications, in group A, anastmotic leakage was most likely to be observed (5.9%), and surgical site infection was the major complication observed in group B (6.0%). Urinary dysfunction, urinary tract infection, abdominal incisional hernia, and postoperative bleeding were seen only in the group A, on the other hand, venous thrombosis, pneumonia and delirium in group B.The present study showed that the short-term outcomes, including overall postoperative complication rates, mortality rates were similar between elderly and non-elderly patients. Furthermore, the details of the perioperative course and length of hospital stay were similar between the groups. Therefore, our results suggest that LAC is a safe and feasible regardless of the age of the patient.P = 0.587). Anastomotic leakage (5.9%) and surgical site infection (2.0%) were main complications in Group A. Surgical site infection was the most frequently diagnosed complication in Group B, followed by ileus, leakage, diarrhea and delirium. Moreover, no mortality was observed in both groups. Similar results were observed in previous reports. For example, Inoue et al. evaluated efficacy and safety of laparoscopic surgery in elderly patients with colorectal cancer [n = 48) and non-elderly patients  and evaluated the demographics and disease-related operative and prognostic data. They found that the postoperative complications were observed 14.0% in less than 75 years of age group and 20.8% in 75 years or older group (p = 0.299). Moreover, the mortality rate was similar between less than 75 years of age group and 75 years or older group . Chautard et al also reported similar results [p = 0.299). There was no mortality. On the other hands, Kang et al. evaluated the short-term outcomes of LAC in 578 patients and divided them into 2 groups. When using cutoff value of 75 years old, overall comorbidity rate is similar between elderly and non-elderly patients . However, the severity of the complications were tend to be higher in elderly group  [The overall complication rates were 19.0% in Group A and 15.7% in Group B. There were no statistically significant differences (l cancer . They co results  They cony group) . These dIn the present study, the perioperative course, such as operation time, intraoperative blood loss, and length of the hospital stay, was similar between two groups. Previous reports demonstrated similar results –33. On tWhen interpreting our results, special attention is required, because there are several potential limitations associated with this study. First, this study was a retrospective study with a limited sample size, despite patients data were collected in multi-institutions. For example, enhanced recovery after surgery (ERAS) protocol may improve length of stay and morbidity of the patients. However, we did not collect the ERAS protocol data. Further study will focus on this issue. Second, the definition and classification of morbidity were different from those used in the previous studies. These differences might have affected the results and discussion. Third, we could not deny the possibility that the elderly people in the present study might be selected and fit for surgery. In the present study, the surgical indication was determined by physicians, including an anesthesiologist, who took into consideration the activities of daily living, performance status, medical history, physical examinations, and organ functions, as is done in general community hospitals. However, there is a possibility that only patients with good status were selected because the morbidity after colorectomy has been reported to range from 10 to 20%, and the complications are sometimes fatal. Actually, although the ASA physical status was significantly different between two groups, Charlson score and body mass index were similar between the two groups. Moreover, the surgical operations are very heterogeneous and different between the two groups. The number of rectal resections is significantly higher in non-elderly patients and this is a bias for duration of surgery, minor and major complications. Considering these limitations of the present study, further studies should focus on which patients are candidates for LAC and will do well after LAC.In summary, the short-term outcomes of LAC were almost equal in the elderly and non-elderly patients in this study. Therefore, it is unnecessary to avoid LAC in elderly patients who may be good candidates for LAC, simply because of their age.The short-term outcomes of safety and feasibility of LAC were almost equal in the elderly and non-elderly patients. Therefore, it is unnecessary to avoid LAC in elderly patients who may be good candidates for LAC, simply because of their age.


Sarcopenia is a chronic condition that is associated with aging and characterized by a reduction of muscle mass, strength, and function. Sarcopenia is prevalent in patients with chronic kidney disease (CKD) and associated with increased morbidity and mortality, as well as cardiovascular complications.To investigate the prevalence of sarcopenia in patients with CKD not yet on dialysis and its correlation with clinical and laboratory variables and inflammatory markers.A total of 100 patients of both sexes aged over 18 were evaluated. Sarcopenia was defined using the criteria of the European Working Group on Sarcopenia in Older People (EWGSOP) and of the Foundation for the National Institutes of Health (FNIH) Sarcopenia Project. Sociodemographic and clinical data, activities of daily living, functional capacity, and physical activity were also evaluated. Inflammation was assessed by the serum levels of high-sensitivity C-reactive protein (hsCRP) and interleukin (IL) 4 and 6.The prevalence of sarcopenia was 11.9% and 28.7% using the EWGSOP and FNIH criteria, respectively. Sarcopenia was more prevalent in the more advanced stages of CKD  and associated with worse performance in activities of daily living (p = 0.049), lower walking speeds (p < 0.001), and higher body mass indexes (BMIs) (p = 0.001) in the non-adjusted model. In addition, patients with sarcopenia had lower functional capacity (p = 0.012) and higher prevalence of physical inactivity (p = 0.041) compared with patients without sarcopenia. After adjustment for confounding variables, sarcopenia was still significantly correlated with walking speed (p = 0.004) and BMI (p = 0.002). HsCRP levels were inversely correlated with appendicular lean mass adjusted for BMI (p = 0.007) and were also positively associated with BMI (p = 0.001). IL4 levels were positively correlated with walking speed (p = 0.007) and lean mass in the lower limbs (p = 0.022).Sarcopenia is common in patients with CKD, particularly in the most advanced stages of the disease. We observed an association between the levels of inflammatory markers and peripheral lean body mass, physical performance, and BMI. This association between sarcopenia and modifiable factors highlights the importance of early diagnosis and the implementation of therapeutic measures to minimize adverse outcomes in patients with CKD not yet on dialysis. The percentage of older people in the population has increased, which emphasizes the need to understand the degenerative processes that occur with advancing age . One of Sarcopenia is an impaired health state that is characterized by locomotor disorder, increased risk of falls and fractures, difficulty in performing activities of daily living (ADLs), disability, loss of independence, and increased risk of death –5.The cause of sarcopenia is multifactorial and usually associated with environmental factors, chronic diseases, activation of inflammatory mediators, physical inactivity, mitochondrial abnormalities, loss of neuromuscular junctions, a decrease in the number of satellite cells, and hormonal changes .A high prevalence of sarcopenia has been reported in developed and developing countries, and this disorder affects both healthy individuals and individuals with chronic diseases, including hypertension, diabetes, and chronic kidney disease (CKD) –9.In CKD, sarcopenia may affect approximately 37% of dialysis patients . HoweverData from the literature show that some inflammatory markers such as IL6, CRP and tumor necrosis factor (TNF) alpha were associated with sarcopenia , and in In recent years, different definitions of sarcopenia have been proposed, and there is no consensus on its characterization. The diagnostic criteria of the European Working Group on Sarcopenia in Older People (EWGSOP) were proposed in 2010 Considering the limited number of studies evaluating sarcopenia in patients with CKD not yet on dialysis and the potentially unfavorable outcomes associated with this syndrome, the objectives of this study were to determine the prevalence of sarcopenia in patients with CKD on conservative treatment using two diagnostic criteria and examine the correlations between sarcopenia, clinical and laboratory variables, and inflammatory markers. Additionally, we also evaluated the association between inflammatory markers and clinical variables related to sarcopenia.This cross-sectional, convenience sample based study evaluated 100 patients from the CKD outpatient clinic of the HIPERDIA Center of the IMEPEN Foundation. This foundation is a secondary care facility that is specialized in the treatment of patients with hypertension and high risk of cardiovascular disease, diabetes mellitus types I and II with poor metabolic control, and patients with CKD not yet on dialysis. The study was approved by the Ethics and Research Committee of the Federal University of Juiz de Fora. Signed informed consent was obtained from all study participants prior to data collection. Inclusion criteria for study enrollment included being an ambulatory male or female adult who were aged over 18, with CKD on conservative treatment. Contraindications to participate in the study included patients with limited performance of tests necessary for assessment of muscle strength and function due to severe neuropathy, liver disease, stroke sequelae, arthritis, arthrosis, amputations, severe chronic obstructive pulmonary disease, Parkinson's disease, cancer, and HIV/AIDS.2 (stages 2 and 3A) and those with < 45 mL/min/1.73m2 .CKD was defined and classified according to the criteria of KDIGO , and theSystemic hypertension was defined as a systolic blood pressure (BP) equal to or greater than 140 mmHg and a diastolic BP equal to or greater than 90 mmHg or the use of antihypertensive medications . DiabeteThe study participants completed a questionnaire that addressed sociodemographic characteristics, ADLs using Lawton’s scale , functio2. A state of low muscle mass was assigned to cases in which the ALMI values were lower than 7.26 kg/m2 for men and lower than 5.5 kg/m2 for women. In the definition of sarcopenia proposed by the FNIH, the ALM was divided by BMI. A state of low muscle mass was assigned if the values were lower than 0.789 for men and lower than 0.512 for women [To evaluate muscle mass, the patients were subjected to bone densitometry with full-length acquisition via dual-energy X-ray absorptiometry using a GE Lunar Prodigy Primo device. To determine low muscle mass, the appendicular lean mass index (ALMI) was measured following the criteria established by Baumgartner  and advoor women .A handgrip was used to evaluate muscle strength, and the cutoff point was < 30 kg for men and < 20 kg for women, according to the EWGSOP criteria. The criteria of the FNIH uses a cutoff point of < 26 kg for men and < 16 kg for women.Muscle performance was evaluated by calculating walking speed over a distance of 3 meters, and a speed of < 0.8 m/s indicated low performance using both criteria.The cutoff points for low muscle mass, muscle strength and performance, according to each one of the criteria, are detailed in Blood samples were collected after 12 hours of fasting for evaluation of blood count, albumin, glucose, total cholesterol and fractions, triglycerides, 25-hydroxyvitamin D, parathyroid hormone, calcium, phosphorus, and creatinine. High-sensitivity C-reactive protein (hsCRP) and interleukin (IL) 6 levels were measured to evaluate inflammation. IL4 was used as an anti-inflammatory marker. HsCRP levels were measured using immunoturbidimetry, and IL4 and IL6 levels were measured using Enzyme-Linked Immunosorbent Assay (ELISA). The urine protein-to-creatinine ratio was determined from a single urine sample per patient, and values > 0.20 mg/g were considered abnormal.The results were expressed as mean and standard deviation for continuous variables unless otherwise specified. Categorical variables were expressed as percentages.Sarcopenia was defined using the classification criteria of the FNIH because this classification adjusts the ALM by BMI and not simply by height.The differences between the groups at baseline were assessed by bivariate analysis using the chi-square test or the t-test, depending on the variables analyzed. Logarithmic transformation was applied to IL4 and IL6 in all analysis, since these data did not present normal distribution. Although hsCRP did not present normal distribution as well, logarithmic transformation was not adequate since it generated negative values for values lower than 1. Median and inter-quartile interval was used to summarize this marker.Box-plots were used to show the distribution of the inflammatory markers in the two groups. Box corners represented the first (lower corner) and third (upper corner) quartiles, and median represented by the line inside boxes. Whiskers represented lower and upper theoretical limits.Spearman’s correlation coefficient was used to assess the associations between hsCRP, logarithm (Log) IL 4 and sarcopenia related variables.The likelihood of sarcopenia given its criteria, adjusted for possible confounding variables, was evaluated using a multivariate logistic regression model with a confidence interval of 95%. A hierarchical approach for model adjustment was adopted using the variables that were significantly associated with sarcopenia in the bivariate analysis. The ALMI variables adjusted for BMI and lean mass in the lower limbs were excluded from this model because of the high collinearity with the sex variable, which interfered with the analysis.Version 21.0 of the SPSS software was used for data analysis. P-values < 0.05 were considered statistically significant.In the population studied, the mean age was 73.59 ± 9.22 years, and 58.4% of the participants were women. There was a predominance of stages 3B (37%) and 4 (29%) of CKD. All patients had hypertension and 53.5% had diabetes.The prevalence of sarcopenia was 11.9% using the EWGSOP criteria and 28.7% using the FNIH criteria. The prevalence of sarcopenia was 34.5% in stages 2 and 3A of CKD and 65.5% in stages 3B, 4, or 5. When we analyzed the components of sarcopenia separately, we observed that 44% of patients had reduced muscle mass, 9% reduced muscle strength, while 69% of patients had reduced muscle performance. The clinical and sociodemographic characteristics of the total study population and the groups with and without sarcopenia are shown in The patients with sarcopenia were older (p = 0.001), showed worse performance in ADLs (p = 0.049), had lower walking speeds (p <0.001), had higher BMIs (p = 0.001), had less lean mass in their lower limbs (p = 0.049), and had less ALM when adjusted for BMI (p < 0.001) in the unadjusted model. In addition, these patients had worse functional capacity (p = 0.012) and a higher prevalence of physical inactivity (p = 0.021).Moreover, the patients with sarcopenia tended to have higher levels of triglycerides (p = 0.053), significantly lower levels of serum creatinine (p = 0.001), and a non-significantly difference of proteinuria  compared with patients without sarcopenia .Regarding the inflammatory markers, we observed that patients with sarcopenia showed a trend of higher levels of hsCRP and lower levels of the anti-inflammatory cytokine IL4. However, there was no difference in the levels of IL6 between the groups .The hsCRP levels were inversely associated with ALM adjusted for BMI , and they were also positively correlated with BMI . IL4 levels showed a positive correlation with walking speed  and lean mass in the lower limbs  .In the multivariate logistic regression model, after adjusting for age, sex, ADLs , walking speed, BMI, functional capacity (SF-36 questionnaire), level of physical activity (Minnesota questionnaire), and estimated glomerular filtration rate, sarcopenia was still significantly correlated with walking speed  and BMI  .The main findings of our study were the demonstration that in patients with CKD not yet on dialysis, the prevalence of sarcopenia varied according to the diagnostic criteria used, and the results suggest that the EWGSOP criteria underestimated this prevalence in the studied population. We also observed a relationship between increased prevalence of sarcopenia and worsening of renal function. The inflammatory markers analyzed were associated with sarcopenia and associated clinical variables as well, mainly modifiable factors such as walking speed and BMI.Sarcopenia, which is characterized by the progressive, age-related loss of muscle mass coupled with a decline in muscle function and physical performance , is gainIn this study, we aimed to evaluate the prevalence of sarcopenia in patients with CKD not yet on dialysis using two diagnostic criteria. According to the EWGSOP criteria, in which the definition of low muscle mass is adjusted to the squared height, the prevalence of sarcopenia in the general population is approximately 30% and might reach 50% in individuals aged over 80 . Using tIn our point of view, the criteria proposed by the FNIH are the most appropriate to be used in clinical research not only for being more representative of the general elderly population, but also for being the first criteria that observed an association with walking speed, a clinical outcome directly associated with muscular disability. Sensitivity analysis indicated that obesity influenced the relationship between muscle mass and strength, which suggests that the adjustment of the muscle mass by BMI would be more appropriate .Several studies have reported correlations between the increased prevalence of sarcopenia and worsening kidney function, and there is evidence of an association between sarcopenia and albuminuria –26. HereIn our study, CKD patients with sarcopenia had worse physical performance, which was reflected by low walking speed, worse performance in ADLs, less functional capacity, and a higher prevalence of physical inactivity compared with patients without sarcopenia. Published data have reported an association between sarcopenia and unfavorable outcomes, including physical inactivity, poor functional capacity, increased risk of falls, and death ,4, 27–29In patients with CKD and obesity, the production of inflammatory mediators by adipose tissue is associated with an increased prevalence of cardiovascular complications and increased mortality . Thus, tWe have shown evidences of the association between sarcopenia and some clinical variables with inflammatory markers. Our results suggested that there was a trend towards higher levels of hsCRP and lower levels of the anti-inflammatory cytokine IL4 in patients with sarcopenia, however, there was no difference in the levels of IL6 between the groups. We also observed inverse associations between hsCRP levels and peripheral muscle mass. IL4 was positively associated with walking speed and lean mass in the lower limbs. It is well described in the literature that the oxidative stress and increased levels of inflammatory mediators are two possible mechanisms contributing to the pathogenesis of sarcopenia . IncreasOur study has some limitations. The small sample size and cross-sectional nature of this study limited the establishment of a causal relationship between sarcopenia and patients with CKD not yet on dialysis. Furthermore, the evaluation of eGFR using the creatinine based CKD-EPI equation might have been influenced by the muscle consumption associated with sarcopenia. The exclusion criteria were many and very broad, which could have probably lead to a selection bias and to an underestimation of the prevalence of sarcopenia. Finally, considering the regression model, we emphasize that the findings related to walking speed and BMI should be interpreted with caution, since they are variables involved in the sarcopenia classification criteria.In summary, sarcopenia was common in patients with CKD not yet on dialysis in this study, particularly during the more advanced stages and the EWGSOP criteria underestimated its prevalence. We observed correlations between inflammatory markers with ALM adjusted by BMI, physical performance and BMI. The association of sarcopenia with modifiable factors highlights the importance of early diagnosis and implementation of therapeutic strategies to minimize adverse outcomes in patients with CKD not yet on dialysis. The prevalence of sarcopenia is expected to increase as the population ages, which calls for the development of prospective studies with larger sample sizes to elucidate the correlation between sarcopenia and CKD.S1 File(XLS)Click here for additional data file.


The association between diet and obesity has been widely studied and it continues to be controversial; however, the extent to which cardiorespiratory fitness (CRF) acts as a confounder or mediator in this relation has not been analyzed. The aim of this study is to examine if the relation between diet and obesity is mediated by CRF. In this cross-sectional study, fat mass (by electronic bioimpedance) was measured in 320 schoolchildren, aged 9–11 years. Diet was measured through two computerised 24-h dietary recalls and CRF was assessed by the 20-m shuttle run test. Simple mediation analyses were fitted. CRF acts as a partial mediator in the negative relationship between dietary factors  and fat mass. The percentage of mediation ranged from 24.3 to 33.2%. Thus, Spanish schoolchildren with higher levels of energy and macronutrients intake had lower adiposity levels, especially when they had good levels of CRF. Childhood obesity has reached epidemic proportions worldwide ,2,3. In Obesity occurs when energy intake exceeds energy expenditure. The development of obesity is mediated by multiple genetics that influence the susceptibility of a given child to become obese, and environmental factors, which seem to play major roles in obesity development ,6. Diet Evidence from several reviews ,7,14 hasHowever, there is a lack of evidence regarding the association between CRF and diet factors, both key variables for maintaining the energy balance.Mediation analysis allows us to estimate the association between two factors, and the extent to which a third variable could modify, mediate, or confound the association. Due to the controversial relation found in the literature between diet, cardiorespiratory fitness, and obesity in children, and the reported relationship between CRF and body fat, we hypothesized that CRF could act as a mediator in the relationship between diet and obesity. To our knowledge, no study has examined if the relationship between diet and obesity in children is attenuated or mediated by CRF. The aim of this study was twofold: first, to assess the association of different components of diet with body composition variables in 9–11 year-old Spanish children, and second, to explore the mediatory influence of CRF on this association.A cross-sectional analysis was conducted of the baseline measurements (September-November 2010) of a cluster-randomised trial . The Clinical Research Ethics Committee of the ‘Virgen de la Luz’ Hospital in Cuenca, as well as the Director and Board of Governors (Consejo Escolar) of participating schools, approved the study protocol. Written consent was provided by the parents for the participation of their children. A total of 320 fifth graders, 9–11 years old, from public schools in the province of Cuenca, Spain, were included.The protocol explained that participants completed most of the variables assessment in the first session . In a second session (another day in the same week), only a second 24-h dietary recall was measured. More information has been reported previously .2). Fat mass (FM), expressed as the percentage of body fat, was estimated using a bioimpedance analysis system . Bioimpedance analysis by the BC-418 Tanita system had showed a good correlation coefficient (r = −0.87) with the reference method, dual energy X-ray absorptiometry (DXA), in %fat estimate for total body [2—in kg/m2) was calculated. This index has been widely used in studies in children. It allows for a more exact comparison between fatness and BMI, since they are both computed and expressed by dividing fat mass and weight by squared height in metres. A recent study showed that FMI is a stronger predictor of cardiovascular mortality than FM [Participants were weighed twice whilst wearing light clothing, using a digital scale  with an accuracy of 100 g. Participants’ height was measured twice without shoes, using a wall-mounted stadiometer (SECA 222) to the nearest 0.1 cm. The mean of each of these two measurements was used to calculate BMI . The YANA-C was completed autonomously by participants, with two or three research members on hand to provide assistance if required, and to check, when children had completed the questionnaire, in the overview screen extreme values or missing data such as intake of beverages, bread, sauces, etc. The YANA-C has been previously shown to have moderate to good levels of reliability and validity . Total d−1, and this was increased by 0.5 kmh−1 min−1 (stage duration = 1 min). The test finished when the child failed to reach the end line at the same time as the audio signal, and the last half stage completed  was recorded as an indicator of children´s CRF. VO2 max (mL/kg/min) was calculated using the Léger protocol [CRF was assessed by the 20-m shuttle run test, in which participants have to run between two lines 20-m apart, while keeping pace with audio signals emitted from a pre-recorded compact disc. The initial speed was 8.5 kmhprotocol .t-test for continuous variables and Pearson χ2 for categorical variables.The distribution of continuous variables was checked for normality before the analysis. Sex differences in descriptive data were assessed by the Student’s Partial correlation coefficients were estimated to examine the relationship between body composition variables, CRF, and dietary factors, controlling for age and sex. The variables CRF, EI/weight, carbohydrate/weight, protein/weight, and fat/weight were categorized as low (first quartile), medium (second and third quartiles), or high (fourth quartile). ANCOVA models were fitted to test differences in FM by categories of CRF and dietary factors, controlling for age and sex (model 1), and with further adjustment for EI/weight, carbohydrate/weight, protein/weight, fat/weight, or CRF, depending on the fixed factor (models 2–6). Pairwise post-hoc hypotheses were tested using the Bonferroni correction for multiple comparisons.Z test of the null hypothesis where the IE is equal to zero was performed. Finally, the percentage of mediation was calculated with the ratio of the indirect (a * b) to the total effect (c).To examine whether the association between dietary factors and obesity was mediated by CRF, a mediation analysis was conducted using the PROCESS macro for SPSS  . The goap ≤ 0.05 was used. All statistical analyses were performed using the software IBM SPSS 23 .A bilateral criterion for statistical significance of p = 0.003) and they had a higher percentage of fat mass than boys (p < 0.001). CRF performance was better among boys (p < 0.001). The protein/weight ratio was significantly higher in boys than in girls.p < 0.01). Total EI was only associated with FM (p < 0.01). The percentage of energy from proteins was positively correlated with FM and WC (p < 0.05). Positive correlations were observed between CRF and dietary factors, while negative correlations were found between CRF and body composition variables (p < 0.001).Partial correlation coefficients between body composition variables and dietary factors, controlling for age and sex, are shown in No changes in the direction or significance of partial correlation coefficients were found when examining the relationship between body composition variables and dietary factors controlling for CRF, age, and sex, and thus, CRF is likely not a confounding variable in the association between diet and obesity (data not shown).Mean differences in FM according to CRF categories, controlling for age and sex (model 1), are shown in Mean differences in FM according to categories of dietary factors, controlling for age and sex (model 1), are shown in p < 0.001). In Equation (2), the regression coefficient of the dietary factor on the dependent variable, FM, was significant (p < 0.001). In the last regression model, CRF was negatively related to FM (p < 0.001), but when both the dietary factor and CRF were included in the model, though the regression coefficient decreased, it remained statistically significant. To confirm the mediator role of CRF, both IE  and the Sobel test (p < 0.001) were significant. The percentage of the total effect mediated by CRF in the relationship between dietary factors and FM ranged from 24.3% and 33.2%. The result of the mediation analysis between CRF, diet, and other adiposity variables measured  showed similar mediation effects (Mediation analysis diagrams are depicted in  effects .The relation between obesity and diet has been extensively analyzed, but the effect of CRF as a mediator has not been studied. The present study is, to our knowledge, the first to evaluate the mediating role of CRF in the relation between dietary factors and adiposity in children. Our data show that children in the lowest CRF category have higher FM than children in higher categories of CRF. Similarly, children with the lowest EI/weight, carbohydrate intake/weight, protein intake/weight, and fat intake/weight showed the highest FM compared to children with higher intakes. Additionally, our data showed that CRF is a partial mediator in the relation between energy and macronutrient intakes with obesity.The relationship between CRF and obesity is well known. Some systematic reviews have reported a consistently negative association between CRF and excess body fat ,7,14 meaSeveral studies have tried to elucidate the relation between diet and adiposity; however, this relation continues to be controversial . Our resFew studies have investigated the relation between dietary factors and CRF in children or adolescents. Our data showed a positive association between total EI and CRF. This finding is in line with previous research, which found a positive association, only in boys, between total EI and CRF with similar analytical techniques . AnotherIn our study, children with better CRF reported a higher intake of carbohydrates, proteins, and fats. Previous studies found better CRF in children who had medium or high adherence to the healthy Mediterranean diet , and chiOur mediation analysis offers new insight into understanding the relationship between CRF, diet, and obesity, suggesting that the diet/obesity relationship is partially mediated by CRF. This supports the hypothesis that children with medium or high levels of CRF, and elevated intakes of energy and fat, are less prone to be obese than children with lower CRF and a lower intake of energy and fat.The mediator role of CRF between cardiometabolic risk and adiposity has been demonstrated, since CRF attenuates the cardiometabolic risk scores in obese children . AnotherThe results of our study provide further evidence supporting that the effect of diet on obesity is partially mediated by fitness in 9 to 11 year old Spanish children. This means we can expect improvements in adiposity levels in obese children associated with interventions aimed at improving fitness with no changes in dietary factors.Since fitness has been shown in several reviews to be very related to high-intensity physical activity ,16,37, oThe main limitation of our study is its cross-sectional design, which prevents us from making causal inferences. Prospective studies could confirm or broaden our results. Secondly, the use of self-reported dietary data could suffer from underreporting or unintentional measurement errors, especially in children . To miniOur findings support that energy and fat intake are negatively associated with obesity, and that this relation is partially mediated by CRF. This is important from a public health point of view because they indicate that diet modifications could result in higher weight loss if they were associated with actions aimed at improving fitness in children.


The human brain is a complex network of interacting regions. The gray matter regions of brain are interconnected by white matter tracts, together forming one integrative complex network. In this article, we report our investigation about the potential of applying brain connectivity patterns as an aid in diagnosing Alzheimer's disease and Mild Cognitive Impairment (MCI). We performed pattern analysis of graph theoretical measures derived from Diffusion Tensor Imaging (DTI) data representing structural brain networks of 45 subjects, consisting of 15 patients of Alzheimer's disease (AD), 15 patients of MCI, and 15 healthy subjects (CT). We considered pair-wise class combinations of subjects, defining three separate classification tasks, i.e., AD-CT, AD-MCI, and CT-MCI, and used an ensemble classification module to perform the classification tasks. Our ensemble framework with feature selection shows a promising performance with classification accuracy of 83.3% for AD vs. MCI, 80% for AD vs. CT, and 70% for MCI vs. CT. Moreover, our findings suggest that AD can be related to graph measures abnormalities at Brodmann areas in the sensorimotor cortex and piriform cortex. In this way, node redundancy coefficient and load centrality in the primary motor cortex were recognized as good indicators of AD in contrast to MCI. In general, load centrality, betweenness centrality, and closeness centrality were found to be the most relevant network measures, as they were the top identified features at different nodes. The present study can be regarded as a “proof of concept” about a procedure for the classification of MRI markers between AD dementia, MCI, and normal old individuals, due to the small and not well-defined groups of AD and MCI patients. Future studies with larger samples of subjects and more sophisticated patient exclusion criteria are necessary toward the development of a more precise technique for clinical diagnosis. Alzheimer's disease (AD), a neurodegenerative disorder characterized by progressive dementia, is the seventh leading cause of death in the United States . MCI consists of heterogeneous symptomatology, and includes prodromal AD stages as well as mild stages of other types of dementing disorders  criteria by Dubois et al. , the diaThe diagnosis of MCI due to AD is possible nowadays  of healthy and pathological conditions . We analyzed DTI data of 15 AD patients, 15 MCI patients, and 15 healthy volunteers, and performed pattern classification of the three categories of subjects based on graph measures. We considered pair-wise class combinations of subjects and defined three separate classification tasks, i.e., AD-CT, AD-MCI, and CT-MCI. An ensemble classification module was used to perform the classification tasks. A limitation of this study is the small sample of amnesic MCI, as those could be a mix of people with AD and other dementing disorders such as dementia with Lewy body dementia. Due to the limited sample size, this study can be regarded as a “proof of concept.”The study was performed in three stages: data collection and processing, feature extraction, and classification. Data acquisition was performed in an MR scanner, and data processing included a preprocessing phase containing realignment, coregistration, normalization, and segmentation of the data. Fractional anisotropy based tractography, and feature extraction was performed based on graph theory by calculating local network centrality measures Freeman, . Patternb-value 1000 s/mm2.Forty-five adults consisting of 15 AD patients, 15 MCI patients, and 15 healthy volunteers were recruited for DTI data acquisition. DTI scans were acquired in the Institute D'or  on a Philips Achieva 3.0 Tesla MR scanner, using a spin echo (SE) sequence with the following parameters: repetition time (TR) = 5620 ms, echo time (TE) = 65 ms, flip angle = 90°, acquisition matrix = 96 × 96 with a spatial resolution of 2.5 × 2.5 mm, 60 transversal slices with thickness = 2.5 mm, 32 gradient directions, and Mini Mental State Evaluation (MMSE),Span  forward and backward,Clock Drawing Test (CDT),Verbal Fluency (semantic and letter),Family Pictures,Geriatric Depression Scale  scanning sequence, with the following parameters: TR = 7.16 ms, TE = 3.41 ms, flip angle = 8°, acquisition matrix = 480 × 480 with spatial resolution 0.5 × 0.5 mm, and 340 sagittal slices with thickness of 0.5 mm.The DTI data was preprocessed with realignment, coregistration, and normalization using the software, SPM8 Friston, , and segij) value of the edge to describe the strength of the connectivity of Brodmann areas i and j. We constructed the connectivity matrix as a weighted matrix for each subject. As there were 41 Brodmann areas, the maximum number of all possible edges was 820 . The number of nodes (41) was the same for each subject since each brain was parcellated using the same scheme. However, subjects differed in the structure of their graph in terms of both the number and weighting on the edges. The numbers of edges were likely to differ for different graphs as the result of varying strengths and presence/absence of the connectivity of Brodmann areas in the subjects. Figure In graph theory, a graph is defined as a set of nodes and edges  centrality, degree centrality, clustering coefficient centrality, load centrality, and efficiency and node redundancy coefficient Figure . The defi to all other nodes sequentially. Consider a connected weighted undirected graph G =  with n vertices and m edges . Let d denote the length of the shortest path between v and u. The closeness centrality Cv :Closeness centrality indicates how close a node is to all the other nodes in a network , betweenness centrality CB(v)  is the number of shortest paths from s to t, and σv is the number of shortest paths from s to t that pass through v.Here σ with n vertices and m edges, connectivity matrix A, Eigen value λ and corresponding eigenvector × satisfying the condition Ax = λx, the eigenvector centrality Ce(v) :Eigenvector centrality assigns relative scores to all nodes in the network based on the concept that connections to high-scoring nodes contribute more to the score of the node in question than connections to low-scoring nodes. Eigenvector centrality is calculated by assessing how well-connected an individual is to the parts of the network with the greatest connectivity Gould, . Recent  Newman,  of node vth entry in the eigenvector × corresponding to the largest eigenvalue λ (max).The above equation represents the G =  with n vertices, m edges and connectivity matrix A, Katz centrality Ck(v)  between a pair of actors, Katz centrality measures influence by taking into account the total number of walks between a pair of nodes. Katz centrality computes the relative influence of a node within a network by measuring the number of the immediate neighbors (first degree nodes) and also all other nodes in the network that connect to the node under consideration through these immediate neighbors Katz, . It is cA. The powers of A indicate the presence or absence of edges between two nodes through intermediaries. For instance in matrix A4 if the element  = 1, indicates that through some first and second degree neighbors of node 1, nodes 1, and 6 are connected.In Equation (4), α, the attenuation factor, is a value which is chosen to be smaller than the reciprocal of the absolute value of the largest eigenvalue of adjacency matrix G =  with n vertices and m edges . The HITS algorithm :Authority update rule: For a given node v, update of its hub score is the summation of authority scores of all nodes pointing to v which is denoted in Equation (6):Hub update rule: For a given node G =  with n vertices and m edges , the degree centrality CD(v) .Degree  of a node in undirected graphs is the total amount of edges directly connecting that node to any other node. It is given by the sum of numbers of edges connecting the nodes. A node with a higher degree of connectivity may be more relevant to the network in terms of number of connections, but it does not measure the importance of each of those connections. Degree has its neurobiological interpretation: a region with high degree interacts structurally and functionally with many other regions in a brain network , deg (v) is the number of edges incident upon a node.G =  with n vertices and m edges , the clustering coefficient centrality Cv .The Clustering coefficient of a node in an undirected graph is a measure that quantifies the fraction of direct connections between the nearest neighbor nodes that exist out of all possible direct connections amongst those nearest neighbor nodes , The Efficiency of a node in a network is a measure of how efficiently, in terms of path length, information can be exchanged with other nodes. Thus, the efficiency is inversely related to the shortest path length between the nodes and is used to evaluate how easily a node can be reached from other nodes. Therefore, the efficiency of a node is the inverse of the harmonic mean of the distances to other nodes .The redundancy coefficient of node N(i) is the set of neighbor nodes for node i, and E is the set of edges of the network , d et al. , which cThe above mentioned 11 network properties were computed for each node  in the graph to form a vector of 451 features. Feature selection was then performed on the feature vector.5 − 1 = 4) data folds per class, leaving out one-fold per class for subsequent classification. This process was done five times in order to apply classification to all the subjects. We implemented a five-fold nested cross validation (NCV) as the training phase included setting the hyper-parameters of the model and selecting the features. Through NCV , for different classification tasks. As seen, K = 430 maximizes the classification accuracy in both AD-CT and AD-MCI classification tasks. And, K = 110 was found to be the best number of top features to include in the MCI-CT classifier. The features were selected based on their score and p-value. The selected top-K features for each of the classification tasks were considered in the respective classifier, which will be explained in detail in the next part.Feature (attribute) selection is an approach to identify relevant features and reduce the noise in order to increase signal-to-noise ratio and reduce overfitting, by constructing a generalized model through the selections of a subset of features from the original feature set  or incorrectly (i = 0) by the first classifier in the pair, and correctly (j = 1) or incorrectly (j = 0) by the second classier in the pair. The lower the Q is for a pair of base classifiers, the more diversity the pair has. We tested various combinations of base learners and found that the combination of logistic regression, random forest, gaussian naïve bayes, 1-nearest neighbor, and support vector machines performs the best for the defined classification tasks. We then used voting for combining the decisions made by the base classifiers and obtaining the final classification result , is made through voting on all the base classifiers (BCi), each having a weight of wi, as stated in Equation (11) , t Figure . In voti Rokach, .n is the number of base classifiers . The preliminary weights of the base classifiers were first generated within the hyper-parameter setting procedure. We then refined the weights by testing various combinations of weights and determined the best weighting set for each of the classification tasks. Intuitively, we assigned larger weights to more accurate classifiers, or set of classifiers with complementary decision boarders. The entire classification process was performed within a nested five-fold cross validation module, as explained before in the cross validation section. The classification module generates a positive (+1) or negative (−1) label for each subject corresponding to the input labels, e.g., AD = +1 and CT = −1 in AD-CT task. After that, this output can be compared with the input label  in order to measure the success level of the approach. Success in classification is achieved when the output label from the classifier is equivalent to the input label. Accuracy of classification is the percentage of correctly predicted (or detected) output labels for all subjects from both positive and negative input classes.In Equation (11), Recall = TP/(TP+FN). According to Table Precision*Recall)/, in which the precision is the number of true-positives divided by true-positives and false-positives. As it is seen in Table We evaluated our model on 45 subjects, comprising 15 AD patients, 15 MCI patients, and 15 healthy volunteers. A total number of 451 features was calculated for each subject from which 430, 430, and 110 features were selected as the most informative features for AD-CT, AD-MCI, and MCI-CT classification tasks, respectively. Table We further investigated the performance of the ensemble classifier with feature selection by calculating the confidence intervals of various performance metrics. We ran the cross validated ensemble classifier for 100 times for each performance metric, i.e., accuracy, recall (sensitivity), specificity, F-1 score, and receiver operating characteristic area under the curve (ROC AUC), and each of the classification tasks, i.e., AD-CT, AD-MCI, and MCI-CT, and stored the result. Next, we checked whether the performance metric is normally distributed. As expected, we observed that none of the metrics for the classification tasks are normally distributed. Therefore, we used the statistical median for calculating the confidence intervalsWe checked for the top-5 features that were detected within the ensemble classification process for each of the classification tasks, separately. For AD-CT classification task, betweenness centrality at Brodmann Area 2 (primary somatosensory cortex), eigenvector centrality at Brodmann Area 1 (primary somatosensory cortex), load centrality at Brodmann Areas 2 (primary somatosensory cortex) and 27 (piriform cortex), and closeness centrality at Brodmann Area 1 (primary somatosensory cortex) were detected as the top-5 most important features. Katz centrality at Brodmann Area 3 (primary somatosensory cortex), degree and closeness centrality at Brodmann Area 5 (somatosensory association cortex), node redundancy coefficient and load centrality at Brodmann Area 4 (primary motor cortex) were found as the most important features for AD-MCI classification. For MCI-CT classification, we observed the hit centrality, page rank, betweenness centrality, and load centrality at Brodmann Area 6 (premotor cortex) along with hub centrality at Brodmann Area 1 (primary somatosensory cortex) to be the most important features.Our results indicate that complex graph measures can be used as makers to diagnose Alzheimer's disease. Moreover, these results indicate that Alzheimer's disease affects Brodmann areas in the sensorimotor cortex and piriform cortex, where we found abnormalities in out measures. The piriform cortex, whose load centrality has been shown as a good discriminative feature for Alzheimer's disease diagnosis by our results, has an important role in olfactory perception , it is important to point out that abnormalities in node redundancy coefficient and load centrality do not mean variations in the connectivity at that exact location. Degree is the only network measure that is directly correlated to connectivity changes in the specific node (in this case primary motor cortex). As Degree is not one of the abnormal measures, it indicates that abnormal connectivity patterns at primary motor cortex are not a relevant feature for AD diagnosis. The relevant network measures revealed here  indicate that connectivity abnormalities on AD are occurring in parallel (in circuit terms) in brain pathways that cross primary motor cortex, which together generate these network patterns found at the primary motor cortex. In other words, the primary motor cortex does not represent the primary effect, rather than the secondary effect of the pathology.Our findings identified measures in the primary sensory cortex , somatosensory association cortex  and primary motor cortex  as good discriminative features for Alzheimer's disease diagnosis, while measures at the premotor cortex  were identified as good discriminative features for MCI diagnosisTherefore, load centrality, betweenness centrality and closeness centrality were found to be the most relevant network measures in our study, as they were the top identified features at different nodes. Other measures, as eigenvector centrality, Katz centrality, degree centrality, node redundancy coefficient, HITS centrality, page rank and hub centrality were also recognized as relevant features for classifications among Alzheimer's disease patients, MCI patients, and healthy controls.The accuracy value achieved in our study can be compared to what other researches performed using other modalities of MRI, such as structural . Therefore, this study is a “proof of concept” about a procedure for the classification of MRI markers between AD dementia, MCI, and normal old individuals. The reliability of these results can be tested later in a complementary study based on a larger sample size (at least 100 subjects per class). It is also important to remark that the small sample of amnesic MCI could be a mix of people with AD and other dementing disorders, such as dementia with Lewy body dementia. Due to these facts, the moderate classification between control subjects and MCI in this study does not mean an ability of the procedure to disentangle between normality and the prodromal stages of AD. However, although the sample size is small, it is quite encouraging that the proposed ensemble classification framework which included a well-tuned feature selection component and was validated within a five-fold cross validation module, resulted in quite good classification performance. We expect larger sample would help the system to better distinguish between the AD and non-AD groups. A longitudinal study can assign at what time-point in the evolution of the disease each region is more likely to be affected by Alzheimer's disease. Moreover, longitudinal studies may have the potential to reveal first evidences of prodromal Alzheimer's disease. Finally, supervised classification approach requires a set of labeled observations Bishop, , thus maThis study was carried out in accordance with the recommendations of ‘International Guidelines for Biomedical Research involving human beings, Declaration of Helsinki’ and ‘Resolution 196/96, Brazilian National Health Council’. Being a retrospective survey of clinical files, patients did not sign an informed consent, in accordance to Brazilian regulations. The protocol was approved by the ‘Ethics Committee of D’Or Institute for Research and Education'.Conceiving and designing the experiments: AE, JD, RS, PR. Performing algorithmic experiments: AE, JD, DN. Analyzing the data: AE. Data/materials: JD, FT, IB, GC. Writing of the manuscript: AE, JD, DN, RS, PR.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.