دانلود مقاله ISI انگلیسی شماره 36823
ترجمه فارسی عنوان مقاله

پشتیبانی نژادهای آشنایی: برداشت آسیب شناسان گفتار و زبان از زورگویی دانش آموزان با اختلالات طیف اوتیسم

عنوان انگلیسی
Familiarity breeds support: Speech-language pathologists’ perceptions of bullying of students with autism spectrum disorders
کد مقاله سال انتشار تعداد صفحات مقاله انگلیسی
36823 2013 12 صفحه PDF
منبع

Publisher : Elsevier - Science Direct (الزویر - ساینس دایرکت)

Journal : Journal of Communication Disorders, Volume 46, Issue 2, March–April 2013, Pages 169–180

ترجمه کلمات کلیدی
اختلالات طیف اوتیسم - قلدری - آسیب شناسان گفتار و زبان - درک - مداخله
کلمات کلیدی انگلیسی
Autism spectrum disorders; Bullying; Speech-language pathologists; Perceptions; Intervention
پیش نمایش مقاله
پیش نمایش مقاله  پشتیبانی نژادهای آشنایی: برداشت آسیب شناسان گفتار و زبان از زورگویی دانش آموزان با اختلالات طیف اوتیسم

چکیده انگلیسی

Abstract Children with autism spectrum disorders (ASD) are primary targets for bullies and victimization. Research shows school personnel may be uneducated about bullying and ways to intervene. Speech-language pathologists (SLPs) in schools often work with children with ASD and may have victims of bullying on their caseloads. These victims may feel most comfortable turning to SLPs for help during one-to-one treatment sessions to discuss these types of experiences. A nationwide survey mailed to 1000 school-based SLPs, using a vignette design technique, determined perceptions about intervention for bullying and use of specific strategies. Results revealed a majority of the SLPs (89%) responses were in “likely” or “very likely” to intervene categories for all types of bullying (physical, verbal, relational and cyber), regardless of whether the episode was observed or not. A factor analysis was conducted on a 14 item strategy scale for dealing with bullying for children with ASD. Three factors emerged, labeled “Report/Consult”, “Educate the Victim”, and Reassure the Victim”. SLPs providing no services to children with ASD on their caseloads demonstrated significantly lower mean scores for the likelihood of intervention and using select strategies. SLPs may play an important role in reducing and/or eliminating bullying episodes in children with ASD. Learning outcomes: Readers will be able to (a) explain four different types of bullying, (b) describe the important role of school personnel in reducing and eliminating bullying, (c) describe the perceptions and strategies selected by SLPs to deal with bullying episodes for students with ASD, and (d) outline the potential role of SLPs in assisting students with ASD who are victimized.

مقدمه انگلیسی

1. Introduction Autism spectrum disorders (ASD) are characterized by social impairment, communication difficulties, and repetitive and stereotyped behaviors (American Psychiatric Association, 2000). Children with ASD have symptoms that vary from mild to severe and often stand out in school environments due to their unique and uncommon reactions and behaviors in social settings. Children with ASD are a very heterogeneous group (Tager-Flusberg & Joseph, 2003). According to Cappadocia, Weiss, & Pepler (2012), bullying experiences are very common among children with ASD and victimization rates are twice as high as those found in the general population. Research reveals self-reported prevalence rates as high as 75% (Little, 2001) and prevalence rates from other studies ranging from 6% to 55% (Bejerot and Mortberg, 2009, Carter, 2009, Little, 2002, Montes and Halterman, 2007 and Van Roekel et al., 2010). ASD may place students at increased vulnerability in their social environment. 1.1. Bullying Bullying is a form of aggression that involves three characteristics: (a) intent to do harm, (b) repetition of the bullying behavior, and (c) a power imbalance between the bully and victim (Olweus, 1993). The bullying epidemic in schools is a worldwide problem (Aalsma and Brown, 2008 and Monks et al., 2009). Young et al. (2011) stated that the effects of bullying include poorer academic achievement, lower self-esteem and confidence, increased anxiety and depression, declines in physical health, absenteeism, alienation and a lack of social connectedness among students. Furthermore, these authors reported that “students with disabilities are both uniquely vulnerable and disproportionately impacted by the bullying phenomena” (p.1). According to a recently published study on the national prevalence of peer victimization among children with disabilities in the United States, one-quarter to one-third of preschool children with disabilities experienced some form of victimization in schools (Son, Parish, & Peterson, 2012). The authors also reported that rates of peer victimization steadily increased throughout the research period. A recent review of the research by Arseneault, Bowes, & Shakoor (2010) supports the notion that bullying is a global epidemic with severe long-term consequences. The authors concluded that children who were bullied displayed an increase of internalizing problems (e.g. withdrawal, anxiety, social isolation, depression), poorer self-esteem, lower levels of assertiveness, and in severe cases increased suicidal thoughts and actions. 1.2. Types of bullying and characteristics of victims Bullying can be categorized into four different types: physical, verbal, relational, and cyber. Physical bullying involves direct contact between the victim and perpetrator. It includes hitting, pushing, and kicking among other physical acts. Verbal bullying involves the use of hurtful words to another individual such as name calling or malicious teasing. Relational bullying involves using social relationships to cause harm to others through tactics such as spreading rumors, gossip, purposeful exclusion from social groups and peer discrimination. The fourth type is labeled cyber bullying in which technology is used as a medium for bullying. This includes the use of computers, texting, cell phones, Facebook, and Twitter. It is a unique form of bullying because it can be perpetrated anonymously, without direct contact, has a permanence that other types of bullying may not have, and can often be viewed by a large number of people (Wang, Iannotti, & Nansel, 2009). Students with ASD experience all four types of bullying behaviors. Kowalski and Fedina (2011) reported on 24 children with ADHD and Asperger's and found that over 57% of the respondents had been traditionally bullied (physical, verbal and relational) and nearly 22% had been cyber bullied within the past two months. They also reported that 19% of these students were bullied several times a week. Cyber bullying is already a recognized and growing problem in children with ASD according to the authors. They report that victims of cyber bullying tend to have less developed social skills. Kowalski and Fedina suggest that “due to social skills deficits, the Internet and technology provide a more fluid means of interacting with peers and opens up the potential pool of social contacts for children with particular disabilities. At the same time, however, increased online activity raises the probability that the same children will be involved in cyber bullying (p.1202). Victims of bullies have been described as either passive (non-responsive to the aggression) or provocative (responsive to the aggression). Passive victims represent 80% to 85% of victims according to researchers (Craig, 1998, Heinrichs, 2003, Olweus, 1993, Olweus, 2003 and Sutton et al., 1999). A passive victim is described as being physically weaker, having fewer friends, demonstrating poorer peer interactions, displaying social problems, and exhibiting poorer pragmatic skills (Rose et al., 2009 and Rose et al., 2010). Provocative victims are also referred to as bully-victims (Rose, 2011). The victims retaliate to bullying with aggression or coping patterns which mimic bullying behaviors. Some studies suggest because some children with ASD have increased levels of aggressive behaviors (Matson and Nebel-Schwalm, 2007 and Rose et al., 2011), they may actually be more likely to bully other students or be bullies and victims. Montes and Halterman (2007) reported that 26% of the adolescents with ASD in their study were classified as bullies. 1.3. Children with ASD and bullying Regardless of the label of victim, bully or bully-victim, children with ASD are involved in higher rates of bullying experiences than peers without ASD. Children with ASD become easy targets for bullies due to their unique and uncommon social skills and their lack of understanding social cues. For example, unique and uncommon comments, a breakdown in initiating or maintaining conversational topics, or a displayed lack of interest in developing or maintaining peer relationships may lead students with these characteristics to be perceived negatively and more vulnerable to the attacks of bullies. Sofronoff, Dark, & Stone (2011) reported on the first study to examine social vulnerability (gullibility and credulity) and bullying in children with Asperger's Syndrome (AS) using the newly developed Social Vulnerability Scale (SVS) with parents. The study included 133 parents of children with AS who completed scales and questionnaires about their children's anxiety, anger, social skills, vulnerability, behavior problems and bullying. Regression analyses showed that social vulnerability was positively correlated with bullying in children with AS. The authors suggested that parents perceived their own children's deficits in social vulnerability and other students lack of understanding as the main causes for bullying. They also concluded that parents may not be aware of the full extent of bullying in their children (e.g. underreporting) and due to the cross-sectional nature of the study, causality could not be inferred. The study suggested that social vulnerability placed children with AS at highest risk for bullying and victimization. Bejerot and Mortberg (2009) found that unusual behaviors including self-harm, obsessive compulsive actions and tantrums increased a child's risk of being bullied. A clear link exists between the social-pragmatic and cognitive-behavioral communication deficits seen in children with ASD and their likelihood of being bullied. Another issue that contributes to bullying experienced by students with ASD is the fact that sometimes these students may not be aware of their own victimization. Frith and Hill (2004) suggested some children with ASD may not have the ability to accurately interpret bullying situations. They suggested that this may not only encourage the bullying behaviors to continue but also prevent the students from reporting it to adults. Adults and caregivers involved in the lives of children with ASD may need heightened awareness of these issues and be ready to take corrective actions to prevent and eliminate bullying episodes. Unfortunately, research is just beginning to report on mediators of bullying in children with ASD, the perceived seriousness of the bullying and the likelihood of intervention by bystanders and adults. 1.4. The role of school personnel Frisén, Hasselblad, & Holmqvist (2012) interviewed 273, 18 year-old former victims without disabilities and asked them specifically about what stopped bullying episodes in their personal cases. Results showed that the most common response, reported 25% of the time, was support from school personnel. Participants also reported that moving to a new school (23%) and learning new ways of coping (21%) were the other two most common strategies for dealing with bullying. It appears that contacting, confiding, and disclosing to school personnel is one of the important ways to reduce bullying episodes. Numerous school programs with the intent to change the educational environment have been reported for combatting the bullying epidemic (Ttofi & Farrington, 2011). General education teachers and other school personnel (e.g., principals, counselors, speech-language pathologists, auxiliary staff) are actively involved in the lives of students (bullies, victims, bully-victims, and bystanders) throughout the school day. The responsibility of helping victims and reducing bullying behavior often falls on school personnel. Despite the critical role education personnel play in the management and reduction of bullying in schools, they are often unsure, untrained and unprepared to deal with bullying episodes (Bauman and Del Rio, 2006, Bauman et al., 2008, Blood et al., 2010, Craig et al., 2000, Frey et al., 2011 and Kochenderfer-Ladd and Pelletier, 2008). For example, Nicolaides, Toda, and Smith (2002) administered a questionnaire to pre-service school teachers in order to determine their beliefs about bullying. The results revealed that the majority of pre-service trainee teachers believed bullying was a very critical problem but they also reported feeling more comfortable in supporting victims rather than dealing with bullies and their parents directly. Lee (2006) reported that educators had a difficult time defining bullying or identifying different types of bullying, and Kochenderfer-Ladd and Pelletier (2008) reported that teachers’ perceptions of the bullying experience dictated their likelihood of intervention. If teachers viewed bullying as part of “normative” behavior in the classroom and thought the student should be acting more assertive, they were less likely to intervene and more likely to let student-victims handle the situation alone. Teachers’ perceptions about bullying were related to their choice of intervention strategies. Craig, Henderson and Murphy reported on prospective teachers’ attitudes toward the bullying label, perceived seriousness of bullying and likelihood of intervention when students reported the bullying or teachers witnessed the bullying episode. They used vignettes to describe physical, verbal and social exclusion scenarios. They concluded that teachers were less likely to describe social exclusion as bullying and less likely to intervene in social exclusion episodes when compared with physical and verbal bullying. The authors reported that prospective teachers were less likely to describe the episode as bullying and less likely to intervene in non-witnessed bullying episodes when compared with witnessed episodes for all types of bullying vignettes. Bauman and Del Rio (2006) also examined how different types of bullying affected pre-service teachers’ perceptions and intervention strategies. Using vignettes of bullying scenarios based on physical, verbal, and relational bullying, they showed that teachers considered relational bullying to be the least severe type of bullying than other types of bullying and were less likely to intervene in these situations. Another factor that may affect responses to bullying is teacher familiarity with students (Barnhill et al., 2011, Koegel et al., 2011, Robertson et al., 2003 and Scheuermann et al., 2003). Recent research findings support that teachers’ working experience (number of children they worked with) and training are critical factors in teachers’ positive perceptions about students and the provision of high quality services to children with ASD (Syriopoulou-Delli, Cassimos, Tripsianis, & Polychronopoulou, 2012). No studies have examined the influence of school personnel's frequency of contact, perceptions of seriousness and likelihood of intervention, and specific strategies to be used for bullying in children with ASD. 1.5. The role of the school-based speech language pathologist The American Speech-Language-Hearing Association Schools Survey Report: SLP Caseload Characteristics (2010) showed 88% of all school-based SLPs reported working with students with ASD on their caseloads. The survey also reported the average number of students with ASD seen for intervention services on SLPs’ caseloads was nearly 8 students. SLPs have a pivotal role in directing the enhancement of functional communication in individuals with ASD. According to the Secretary of Education for the United States, bullying is ultimately an issue of school safety (Arne, 2010). Children perform and learn better in safe schools. An environment in which children are not safe minimizes learning while a systemic fear of victimization and violence impact education goals and attainment (Arne, 2010). All school personnel have a responsibility and role in creating safe schools, fostering resilience in students and eliminating victimization and violence. The American Speech-Language-Hearing Association's, Roles and Responsibilities of Speech-Language Pathologists in Schools, Professional Issues Statement (2010) states SLPs provide critical services to support the instructional program at schools. Some of these include: (a) addressing personal, social/emotional, academic, and vocational needs that have an impact on attainment of educational goals; (b) collaboration with other school personnel; (c) unique contributions to the curriculum, (d) advocacy for appropriate programs and services for children and adolescents and (e) leadership roles for ensuring delivery of appropriate services to students. SLPs have unique role in schools with students, often spending time working directly or in small groups in environments completely different than the classrooms, cafeterias, playgrounds, and hallways. Their work, focusing specifically on students and their abilities, changing behaviors, attitudes, and feelings, and personal instruction, allows for greater flexibility than classroom teacher, in terms of unplanned conversations and spur-of-the moment interactions on various topics, problems and interests. While addressing the personal and social/emotional needs of students, SLPs may find themselves addressing topics of bullying and acts of violence. Their role in identification, support, advocacy and intervention at these times can be critical to reducing and/or eliminating abusive behaviors by peers. As SLPs become more informed and educated about recognizing, understanding and appropriate interventions in bullying, they can also become better advocates for the students on their caseloads/workloads and ultimately all students in the schools. Advocacy for children with communication disabilities and collaboration with school colleagues are not only core responsibilities of SLPs but also the foundation for improvement in positive student outcomes. Their roles in responding to students, collecting data, discussions with teachers, and consulting with parents all support instructional program at schools. All school personnel have roles and responsibilities in the prevention of violence and bullying. Studies have reported the roles of school counselors (Bauman et al., 2008 and Jacobsen and Bauman, 2007), school nurses (Cooper et al., 2012 and Liu and Graves, 2011), educational support professionals (e.g. paraprofessionals, maintenance staff, clerical staff, cafeteria staff) (Gulemetova et al., 2011), school guidance counselors (Power-Elliott & Harris, 2012) and school bus drivers (de Lara, 2008). Some research has been conducted to examine the thoughts, feelings, or perceptions of school-based SLPs about bullying. Previous research clarifies the important role of perceptions of educators in intervening in bullying episodes, while recent research using vignette techniques to study perceptions of bullying and the likelihood of interventions by SLPs has been reported with children who stutter (Blood et al., 2010) and children who are English Language Learners (Blood, Robins, Blood, Boyle, & Finke, 2011). SLPs’ direct contact with students with ASD, collaborative roles on school-based teams, and expertise in social and communication skill building, position them to play important roles in assisting in bullying intervention for these students. 1.6. Purpose of this study As reviewed above, school personnel's knowledge, attitudes, contact and beliefs impact their likelihood for intervention in bullying episodes. We wanted to determine the perceptions of SLPs about the bullying problem with children who have ASD when presented with written vignettes. The current study has two main goals: (1) to determine the likelihood of intervention and types of intervention strategies perceived as appropriate by SLPs in eight episodes of bullying (four types of bullying: physical, verbal, relational, and cyber, across two conditions: observed and not observed) in students who have ASD, and (2) to determine if SLPs’ personal experience working with children with ASD (the number of children on their current caseload) related to their perceptions of intervention and strategy choices. This research is a part of a large scale study examining the perceptions, knowledge, confidence, and interventions of SLPs in the area of bullying in schools.

نتیجه گیری انگلیسی

3. Results 3.1. Likelihood of intervention Using the data from the five-point scale, the frequency of all the ratings was obtained. Of the 4,416 responses (552 participants × 8 vignettes), no participants endorsed the “not at all likely” to intervene category. One hundred and ninety-eight (4.5%) SLPs’ responses were in the “not very likely” to intervene category and 289 (6.5%) of their responses were in “somewhat likely” to intervene category. The majority of the responses (89%, 3929) to all 8 vignettes were in the “likely” to intervene category (773, 17.5%) and the “very likely” to intervene category (3156, 71.5%). This indicated SLPs as a group would be likely to intervene in bullying situations, regardless of type of bullying and whether the SLP observed it or the student reported it to the SLP, for students with ASD. The means and standard deviations for the eight vignettes for SLPs’ attitudes toward the likelihood of intervention were also obtained. The group mean for the likelihood of intervention for the observed conditions was 4.81 (SD = 0.6) and 4.74 (SD = 0.6) for the not observed condition. The group mean for the likelihood of intervention for physical bullying with the observed condition was 4.83 (SD = 0.5) and 4.73 (SD = 0.6) for the not observed condition, while the group mean for the likelihood of intervention for verbal bullying with the observed condition was 4.81 (SD = 0.6) and 4.74 (SD = 0.6) for the not observed condition. Similarly, the group mean for the likelihood of intervention for relational bullying with the observed condition was 4.82 (SD = 0.6) and 4.74 (SD = 0.5) for the not observed condition, while the group mean for seriousness for cyber bullying with the observed condition was 4.83 (SD = 0.6) and 4.81 (SD = 0.5) for the not observed condition. To determine significant differences in SLPs’ ratings of the likelihood of intervention, a 2 (Condition – observed versus not observed) × 4 (Bullying Type – physical, verbal, relational, cyber) MANOVA was conducted. Effect sizes for the MANOVA model, eta squared (η2), were computed ( Cohen, 1988). Results revealed no significant differences between the group means for the observed and not observed conditions, F(1, 4415) = 2.21, p = 0.137, no significant differences among the four types of bullying, F(3, 4415) = 0.99, p = 0.436, and no significant interaction between types of bullying and conditions, F(3, 4415) = 0.73, p = 0.642. These data suggested SLPs were likely to intervene regardless of the type of bullying (i.e. physical, verbal, relational, cyber) or if the bullying was observed by the SLP or reported by a student. 3.2. Strategies used 3.2.1. Factor analysis To determine dimensionality and identify latent constructs of the 14 items, an exploratory factor analysis (EFA) was conducted. Examination of the scree plot suggested that a three factor solution was most parsimonious. Attempting to identify the simple structure, a maximum likelihood factoring approach with oblimin rotation was conducted. Oblimin rotation was used because it is recommended for factors that are likely to be correlated. Bullying intervention strategies were retained and considered meaningful if the loading on one factor was greater than 0.60 and the loading was at least. 20 higher than the loading on any other factor (Norris and Lecavalier, 2010, Tabachnick and Fidell, 2007a and Tabachnick and Fidell, 2007b). The 14 items were retained and distributed over three factors accounting for 72.2% of the shared variance (Table 1). Factor 1 was labeled “Reporting/Consulting Activities” and explained 40.7% of the shared variance. It consisted of seven strategies representing the reporting of bullying and consulting with others about the bullying including: “Report the bully to other education personnel,” “Work with other school personnel,” “Talk with onlookers about their responsibility,” “Help onlookers take a more active role to support victims,” “Refer the victim to the school counseling staff for help,” “Work with parents of victims,” and “Work with parents of bullies.” The coefficient alpha computed was. 82, indicating good internal consistency of the items constituting this factor. Factor 2 was labeled “Educating Activities” and explained 21.3% of the shared variance. It consisted of five strategies representing educating the victim about bullying strategies including: “Educate student-victims to report such events,” “Educate student-victims to be more assertive,” “Teach student-victims to pretend not to be bothered,” “Educate student-victims to ignore the other bully(ies),” and “Educate student-victims to blend in better.” The coefficient alpha computed was. 85, indicating good internal consistency of the items constituting this factor. Factor 3 was labeled “Reassuring Activities” and explained 10.2% of the shared variance. It consisted of two strategies representing reassuring the victim including: “Talk with the student-victim and try to calm him/her down,” and “Talk with the student-victim and offer to protect him/her from this happening again.” The coefficient alpha computed was. 81, indicating good internal consistency of the items constituting this factor. 3.2.2. Strategies used by condition and type of bullying The summated mean scores of the 3 dependent variables from the factor analysis were submitted to a 2 (Condition: Observed vs. Not observed) × 4 (Type: Physical, Verbal, Relational, Cyber) ANOVA. Effect size for the MANOVA model, eta squared (η2), was used with the same guidelines mentioned previously from Cohen (1988). For Factor 1 “Report/Consult,” there were no significant differences for the main effect of condition, F(1, 4415) = 2.21, p = 0.137, the main effect of type, F(3, 4415) = 0.99, p = 0.436, or the interaction between type of bullying and condition, F(3, 4415) = 0.73, p = 0.642. These data suggested that all SLPs selected similar Report/Consult strategies, regardless of whether the bullying was depicted as physical, verbal, relational, or cyber, and if the bullying was observed or simply reported by the student. Similarly for Factor 2 “Educate,” there were no significant differences for the main effect of condition, F(1, 4415) = 0.11, p = 0.865, the main effect of type, F(3, 4415) = 1.09, p = 0.366, or the interaction between type of bullying and condition, F(3, 4415) = 0.20, p = 0.987. These data suggested that all SLPs selected similar Educate the Victim strategies, regardless of whether the bullying was depicted as physical, verbal, relational or cyber, and if the bullying was observed or simply reported by the student. For Factor 3 “Reassure,” there were no significant differences for the main effect of condition, F(1, 4415) = 1.02, p = 0.955, the main effect of type, F(3, 4415) = 0.688, p = 0.688, or the interaction between type of bullying and condition, F(3, 4415) = 1.49, p = 0.166. These data suggested that all SLPs selected similar Reassuring strategies, regardless of whether the bullying was depicted as physical, verbal, relational or cyber, and if the bullying was observed or simply reported by the student. In summary, regardless of the type of bullying or if it was reported or observed, SLPs reported similar positive responses to using report/consult, educate, and reassure victims strategies. 3.2.3. Number of children with ASD on SLP's caseloads and strategies used The second research question determined whether the contact with children on caseloads or familiarity with working with children with ASD would relate to the likelihood of intervention and strategy choices. In order to conduct this analysis, SLPs’ responses to the question of “how many children are you currently providing services to with ASD on your caseload” were categorized into five groups. Group 1 consisted of 107 (19.4%) SLPs who provided no services to children with ASD on their caseloads. Group 2 included 129 (23.4%) SLPs who provided services for 1–4 children with ASD on their caseloads. Group 3 consisted of 60 (29%) SLPs who provided services for 5–8 children with ASD on their caseloads. Group 4 included 93 (16.8%) SLPs who provided services for 9–12 children with ASD on their caseloads. Group 5 included 63 SLPs who provided services for more than 13 children with ASD on their caseloads (range 13–36 children). An ANOVA was used to determine significant differences among the groups, with the three factors as the dependent variables and the “children on the caseload” grouping factor as the independent variable. Results revealed significant differences among the five groups for all three factors: the Report/Consult factor F(4, 551) = 34.71, p < .0001, η2 = .20, large effect size; the Educate factor F(4, 551) = 45.73, p < .0001, η2 = .25, large effect size; and the Reassure factor F(4, 551) = 13.17, p < .0001, η2 = .08, medium effect size. Post hoc analyses of the group means were conducted and revealed that SLPs in Group1 (those providing no services to children with ASD) had significantly lower mean scores, p < .0001, than any of the other four groups. Fig. 1 depicts the results of these analyses. There were no other significant differences among the other four groups. SLPs in Group 1 reported lower means scores of 4.0, 3.7, and 4.4, for factors 1, 2, and 3 respectively when compared with the other four groups. SLPs in Group 1 endorsed a greater number of “Neither Yes/No and Maybe Yes (scores > 3.0), than SLPs in the other four groups. SLPs’ in Groups 2, 3, 4, and 5 were more likely to select the “Definitely Yes” category compared with SLPs in Group 1. This significant finding was strongest for providing “Education” activities about different types of strategies. The mean scores for reassuring and reporting among Group 1 were closer to the mean scores for other SLP groups providing services to children with ASD. Image for figure Fig. 1 Fig. 1.