JEK Journal of Earth Kingdom JEK 1. : 38Ae47 ISSN 3024-9821 Mutuality of being in the batak toba community: exploring the maingain tradition in the modern era Aldi Pahal Rizky Sihaloho 1* Department of Anthropology. Faculty of Social and Political Sciences. Universitas Indonesia. * Correspondence: aldi. pahala@ui. Received Date: April 25, 2023 Cite This Article: Sihaloho. Mutuality of being in the batak toba community: exploring the maingain tradition in the modern era. Journal of Earth Kingdom, 1. , https://doi. org/10. 61511/jek. Copyright: A 2023 by the authors. Submitted for posibble open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license . ttps://creativecommons. org/licens es/by/4. Revised Date: June 18, 2023 Accepted Date: June 19, 2023 Abstract This paper explains mutuality of being that is seen through the tradition of mangain . dopts a chil. in Batak Toba society which has progressed over This tradition is familiar for the Batak Toba people who want to do mixed marriage with non-Batak ethnic groups. In the reality, the whole function of mangain is rooted on Aochild adoptionAo. This tradition directs people who receive a Batak Toba clanAiI called it the AuOrang Batak baruAyAi , not only Batak Toba people, to a Dalihan Na Tolu life which is mutually dependent on each other. On the other hand, mangain does not encourage them forget their parents who gave birth to, and nurturanced for, them. Mangain has become an example of a tradition that can strengthen the unity of Indonesia, a plural country, because kinship in here is not only seen from procreation. Diversity has been seen as a source of conflict of interest between groups in Indonesia. The final result of this article showed that mangain tradition accommodates the Batak Toba people love non-Batak people, and vice versa, which can be seen from the implications of the mutuality of being in it. Archival data, writing of academics from various fields up to other forms of writing, became the basis of this Interviews of informants who have been directly involved in the mangain process, even wrote it in a book, then completed this paper. Keywords: ethnic. mangain tradition. mutuality of being Introduction In Indonesia has a variety of cultures which, in that way, is also indicative the existence of various traditions in each culture. Traditions, along with their values, make humans live in a guideline that provides answers to problems that are or will be, happening. The existence of this function encourages tradition to continue to show its existence from generation to generation for the survival of humans, as happened in Batak society. Bruner . observes the continuity of the Batak tradition through his observations from 1957 to 1958 of the life of a 75-year-old elder in Lintong ni Huta Village, and the elder's nephew who grew up in Medan City. The elderly informant is a rice farmer who is illiterate and adheres to animism, while his nephew works as a government official who can speak four European They had different backgrounds, but Bruner saw no fundamental differences in consanguinity practices and ceremonies between the two. Traditions, or adat, have indeed undergone a series of modifications, but their basic values have not changed because they provide support among groups of kin . 1: 509, . The kinship system in Batak society meant by Bruner is Dalihan Na Tolu. Dalihan Na Tolu regulates the life of the Batak people according to the roles and functions occupied by each party (Silalahi, 2. The Dalihan Na Tolu element is the main concern for all parties in carrying out each Batak custom because the relationships within it have been arranged proportionally. This arrangement aims to create regular relationships that have a positive impact on all groups in Batak society, without exception. This can be JEK. VOLUME 1. ISSUE 1 https://journal-iasf. com/index. php/JEK JEK. VOLUME 1. ISSUE 1 seen from one of the traditions that are close to my family life as a Batak person, namely the mangain tradition. The mangain tradition began to become familiar to me when Mawarida Siboro, my mother, designed the mangain tradition because my biological brother, with the initials ABP, was dating a Manadonese with the initials M. This tradition is being planned by the wife of (Al. Sudin Sihaloho, my father, this for ABP it reminds me of the phenomenon of a mixed marriage that occurs in Batak society, especially in my extended family environment. The first son of one of my older mothers (Mawardaida's older siste. , married a Javanese His wife has received clan bones (Mawardaida's biological siste. I, namely Siboro. In addition, one of my brothers-in-law, surnamed Siagian, is also married to a woman of Javanese ethnicity. Another daughter of one of my older mothers (Mawardida's older siste. also married a man of Javanese ethnicity who has received the Batak clan. Naibaho. private tutor is also a man of Javanese ethnicity who has received the Batak clan. Sihite. The facts presented above show that mixed marriages are common practice for Batak people. Before realizing all these facts. I was the type of person who held a conservative view that Batak people should marry Batak people too. This understanding did not come out of nowhere. My parents and siblings, especially those who are elderly, have fed this understanding to me since childhood. One of my older fathers . y father's cousi. , during the Christmas and New Year celebrations three years ago, advised me and ABP to marry other Batak people so that the Batak tradition would not become extinct. The same thing was conveyed by one of my older mothers (Mawaida's older siste. , as well as SS, or my old mother, the wife of . he lat. Ferdinand Sihaloho . ather's older siste. , although the reasons were different. Both of them see that non-Batak people will find it difficult to adapt to all kinds of customs and Batak values. At the start of ABP dating M last year. Mawarida also stated the same thing. From the advice of the parents above. I see a discrepancy between the values that they want to pass on to their children with the reality that is happening in my immediate environment. The increased mobility of the population to various directions on the other hand turned out to be unavoidable so the phenomenon of mixed marriages became commonplace for the Batak people. Besides that, based on the love life experience between ABP and M. I also gained understanding from the non-Batak side of the family. M's parents think that their child does not need to be traditional and given the Batak They are afraid of losing M because they often hear words from their extended family that a person who is given the Batak surname will leave his relationship with the parents who have taken care of him since birth. M's parents' understanding reminded me of various intercultural conflicts that occurred in Indonesia due to stereotypes, such as Islam and Christianity in Ambon in 1999, and Dayak and Madurese which also occurred in the same year in Kalimantan. This fact tarnishes cultural diversity in Indonesia which should provide a value of beauty. Indonesia is filled with various kinds of people, ranging from skin color, generally referred to as race, to various skills contained in culture. This difference becomes a status that cannot be separated from each human being, or Eriksen calls it ethnic identity (Eriksen, 1994: . The facts above reveal that ethnic identity turns out to be a gulf between national unity and unity, in line with M's parents' understanding. This paper wants to convey that the conditions imagined by M's parents are not reality. Mangain does not encourage all new Batak people to disrespect, or even sever, their relationship with their previous parents, unless the mangain is done from a young age or a M became even more valuable when M was appointed by the Batak family because he would become part of the Batak family as a whole. The researcher will frame this problem in Sahlins' concept of mutuality of being. The mangain tradition is no stranger to the Toba Batak people when mixed marriages occur between them and baoa . and boru . Baoa and boru sileban can hold a traditional wedding party with a Toba Batak bride after getting the Toba Batak clan through mangain. The function of the mangain is not only concerned with the issue of mixed marriages. The full functioning of the mangain is rooted in the 'raising a child's part. The new Batak people will become part of the Dalihan Na Tolu kinship JEK. VOLUME 1. ISSUE 1 structure and are allowed to follow every customary procedure in it, both in joy and sorrow (Silalahi, 2. This tradition directs the recipients of the clan and the people of the Toba Batak descent to the Dalihan Na Tolu kinship life which is mutually dependent on one another, in other words strengthening kinship solidarity, in every Batak tradition. Mangain does not encourage all new Batak people to forget the role of their parents who gave birth to and cared for them even though they have become part of the Toba Batak family. Sahlins' opinion in his writing regarding the mutuality of being is in line with mangain because kinship is not merely talking about blood relations, but an effort to love each other from time to time. The new Batak people thus have two different ethnic identities acquired during life, in line with Eriksen's opinion . 4: . , which can be carried out according to conditions and needs in everyday life. Mangain as a tradition can eventually be used as a weapon that can strengthen human relations, especially in Indonesia which is a multicultural country. The following questions are from the problems above. This study was conducted to explain the journey of meaning and function of manga for the Toba Batak community from its inception to its current application. This trip will finally show another dimension of Dalihan Na Tolu, the kinship system of the Toba Batak The dimension in question is an act of mutual affection between Batak ethnic groups and non-Batak as a result of mangain, especially mangain which is intended for the sacred bond of marriage. This reciprocal relationship will then reveal the concept of mutuality being created by Marshall Sahlins which is represented by me through the mangain Methods This study utilized various types of archives, especially sources from writing academics, for helping me find the emptiness of anthropology discussion in the mangain case. The emptiness in question is the absence of an analysis of the concept of mutuality of being in the mangain tradition. Analysis of the mangain tradition, especially in anthropology, has so far focused on the issue of the mobilization of the Toba Batak people who left North Sumatra, causing the tubu sorang magodang mangain tradition to emerge. Other analyzes also discuss details about changes in children's values that change along with the development of the mangain tradition in the Toba Batak community. The author used archive-based qualitative research methods, or secondary data sources, with an anthropological perspective to describe the mutuality of being as seen from the mangain tradition from previous studies. Archives are documents in the form of writing, spoken or pictorial issued by past institutions (KBBI). Zeitlyn . more or less mentions the same thing, "Archives are both the repositories of material . and the materials contained therein. " The existence of this material . can help me in answering questions of research problems when space for outreach to the community is limited due to the Covid-19 pandemic. The archives that are relied on in this study come from previous academic writings from various fields, ranging from anthropology, law, and sociology, to Writings that are not sourced from academic writings are also used to collect data on mangain traditions as a whole. I also use the in-depth interview technique of one of the authors of one of the main materials used in this article to help me in analyzing the author's writings. The main material in question is a book entitled AuPunguan Sihaloho Raja Dohot Boru SejabodetabekAy which was owned by my family because I became a member of the Sihaloho Raja Dohot Boru SejabodetabekAian area that includes Jakarta. Bogor. Depok. Tangerang, and BekasiAiin 2014. The author is Daniel Pantun Sihaloho, while his wife is named Rola Berliana Lumban Toruan. Both are graduates of the Faculty of Law. University of North Sumatra. They are members of Sihaloho Raja Dohot Boru Sejabodetabek Specifically for Daniel, his position in the management of Punguan Sihaloho Raja Dohot Boru Sejabodetabek when the book containing the topic "Mangain Boru" was published was the head of the division. For the customary period 2012-2016. Daniel takes responsibility for the period 2021-2025 and took over the position of general secretary. The author intended to interview Daniel to understand his perspective on his writing. The causal relationship in JEK. VOLUME 1. ISSUE 1 every tradition cannot be understood simply, depending on how one absorbs cultural meaningsAiintentions, motives, beliefs, rules, discourse, and values (Hammersley and Atkinson, 2019: . The information I received turned out to be more dominant from Rola. Daniel said to me that Daniel has the same understanding as Rola because they have been together through life. They were also involved in the mangain process because their first son. Bungaran, married a Manadonese. Daniel never disputed the statements that came out of Rola's mouth, even several times giving approval and additional statements that were lacking from Rola. Daniel still paid attention to my communication with Rola even though he talked with . he lat. Ferdinand Sihaloho who accompanied me to meet Daniel. (Al. Ferdinand also became my informant because he had done mangain. The author's interview ultimately differentiates anthropological work from history because anthropology encourages researchers to ask living informants to find out the empty spaces left by previous archives (Zeitlyn, 2. The results of the interviews have gone through a transcription process so that I can insert any information from the informants in written form in this paper. Results and Discussion Maingain Process: The Practical Case Mangain is the process of giving a Batak surname by a couple of Batak husband and wife to someone who is not of original Batak descent (Hutabalian, 2014. Windi, 2021. Puspitawati & Sihombing, 2. The consequence of giving this surname is the adoption of a person who is given the Batak surname as a child. Several authors, such as Hutabalian . and Windi . , emphasized that adoption cannot be equated with adoption, even though my informants gave a different opinion. Puspitawati & Sihombing's . study of the ethnic reasons for the Toba Batak in Babalan. Langkat, and mangain also supports Rola's statement even though there are different views regarding the value of children in a Toba Batak family. The value of boys in the mangain process for the Toba Batak people in Babalan has changed. This change will be discussed in the next section regarding the position of adopted children. This mangain which is intended for adoption exists, and is fundamental to the current mangain process, even if it is intended for conditions when a Batak marries a non-Batak person. The implementation of mangain, in this case adopting children, is now much simpler than in the past. The mangain stage used to be very long and celebrated in big parties because the parents who adopted the child must be very rich. Wealth encourages them to adopt a small child as an heir, in addition to their main goal being to continue the lineage so that Dalihan Na Tolu will continue to run properly. The initial process carried out by an ancient couple was to determine who would be adopted as a child. The child taken must be of the male gender so that he can carry on the clan passed down by his adoptive father. They can take children from one of the haha anggi . rother or siste. who already has several The children chosen can also come from dongan tubu . elatives or family friend. , the main thing is according to the provisions that have been agreed upon through the extended family discussion process. Currently, the selection of children is more varied because of the existence of orphanages, even Sitompul . confirms the existence of The next stage is informing the mangain plan to relatives of the same clan as the husband's side, from siblings to the level of opung doli . , at least four Informants. Daniel and Rola, became witnesses to the process of work on the body of a magodang. Their son. Bungaran Sihaloho, is married to a Manadonese named Gaby. The Bungaran family decided to give the clan of the previous Bungaran birth mother, namely Simarmata. Bungaran married when Daniel's first wife passed away and was replaced by Rola as the surrogate mother. The decision to be given the Simarmata surname had been discussed previously with Rola. Rola agreed as a form of respect for her late biological mother Bungaran. The rest of the process is exactly as discussed in the previous section. The difference lies in how the Gaby family is invited in the customary process mangain. JEK. VOLUME 1. ISSUE 1 Daniel and Rola try to teach Gaby as a candidate for the first time, or mantu, about Batak customs before meeting the Simarmata family. They were responsible for Gaby's success in becoming a Batak because they had asked the Simarmata extended family for help to be adopted as a child. Gaby then had to keep learning from the family that raised her over time. They weren't burdened with responsibilities in the end because Gaby also had the desire to mingle with the big family that raised her. Gaby madebone, or his uncle. Bungaran, who has raised Gaby as a parent wholeheartedly. Real evidence was seen when Gaby informed her adoptive parents about everything that was happening in life, one of which was when Gaby was pregnant with her first child. Several changes were also made by Gaby in terms of dress to show how she had becomepipeBatak. Gaby wears more closed clothes when there are Batak family events by wearing a sarong compared to when Rola first met Gaby. The sarong worn by Gaby is Rola's form of business because Rola bought it Gaby was also taught to always remember that they have to provide food for every family event, as well as enough mats for the family to have a sit-down event, following the habits of their previous parents. Rola tries to teach Gaby little by little in a way that is good, not intimidating. Rola then reminded her that she did not demand the same thing when Gaby attended her biological family's event. Rola admits that the Bungaran family is close to Gaby's biological family because they ask each other how they are. His biological father Gaby started calling Daniel by his nickname layers, the greeting of Batak men from different surnames, while his biological mother called Gaby eda to Rola, a Batak greeting among women of different clans. Daniel and Rola also call them by special names. Gaby's biological father was called dude based on experience with people of Manado and eastern Indonesiaother. So, the informant confirmed that the process mangain this makes the two different families, even ethnically, unite and respect each other's customs. The act of adopting a child really needs to involve the state government through a legal process in the District Court because it relates to determining the heirs, as stated in the writings of Lusiana . Hariandja . 9: . Parapat in Silaen . , and Langkas Lumbangaol in Banjarnahor et al. The authors above are legal academics at various different universities in Indonesia who view mangain from the point of view of the position of adopted children in Toba Batak customary inheritance law. Mangain in this way is not necessarily carried out through customary processes Mangain for young children also needs to be remembered that the parties involved in mangain are far different between then and now, apart from the government. Mangain at this time is enough to be delivered to hula-hula and bone only. Couples who adopt children can at least invite their dongan tubu and other closest relatives. All ancient people connected with them should be invited to perform mangain as well. The role of religion, especially Christianity, apparently also creates new reasons why young children's mangain is done by Toba Batak families. Puspitawati and Sihombing . stated that the Toba Batak family in Babalan did mangain on the grounds that divorce and polygamous marriage were prohibited in Christianity. So, mangain for young children was and is currently experiencing several changes, both from the parties involved to the urgency that drives the implementation of mangain. The stages of mangain are more detailed, apart from notifications to certain parties, which will be explained next in the explanation about mangain in the body of a magodang because the basic stages between the two are not much Mangain, besides being intended for adoption, can also be done for marriage vows between people of original Batak descent and baoa/boru sileban (Sitompul, 2. Sahlins . stated that the quality of kinship cannot be seen from the production of offspring alone. Some of the cases raised in his study, such as the Korowai and To Pamona people, are in line with this phenomenon mangain amid the life of the Toba Batak people. Appearance mangain at first due to the urgency of the absence of offspring does not seem by Sahlins' view. The adopted child is still related by blood to the adopted parent. The existence of orphanages and hospitals then provides a new dimension that is in line with Sahlins if there are no children to be taken from blood relatives. Play the body of a magodang further emphasizes the mutual relations of the Toba Batak people which are not only JEK. VOLUME 1. ISSUE 1 realized based on blood relations. The hereditary advice from the Toba Batak ancestors is to marry parib which means it is still related biologically. Today's Batak generation shows a rejection of marriage with parib this is considered an ancient arranged marriage that will burden the family life of the two couples who have been closely intertwined for generations. Mangain is considered by Batak elders as a solution for the current generation who prefer to marry someone from another ethnicity, especially with the addition of world progress which increases the mobility of the world's population. The above facts imply that a pair of Toba Batak parents will have a child that I call a "new Batak person. "The term "new Batak people" is meant to describe those who were previously not Batak but have become Batak even though they are considered full Batak people if they have been appointed by a Batak They will establish a relationship like parents with their biological children regardless of blood relations, such as kinship in the Korowai community in Papua New Guinea which was studied by Stasch . 9 in Sahlins, 2. Amalgamation, ethnicity, and identity: some implications The author have touched on historical issues related to today's use of ethnic identity in the early part of this article. History exists, and emerges, to respond to current problems (Eriksen, 1994: . Tradition is part of past history. Tradition is a habit passed down from generation to generation from ancestors because it is considered good to be used as a provision in carrying out life (KBBI). This tradition also creates a new identity, in this case the mangain, which creates the "new Batak people. From the past until now, the Batak always recommend that their children marry Pariban. Marriage with pariban is permitted in the Dalihan Na Tolu principle not only because the surnames of the two partners are different even though they are blood-related. Pariban marriage shows the bond between a man and boru ni bom . aughter of his mother's Batak people are obliged to somba marhula-hula . espect for the wife's famil. , and bones are included in it. The reasons for respecting hula-hula will be explained in the next section in one of the mangain processes. This marriage with the pariban, for the Mandailing Batak people, even began with an arranged marriage that was carried out since childhood, the process of which is known as manyunduti (Yusdiawati, 2. If this mangain process takes place, then the indication is that there is a Batak who does not want to marry a pariban. Sitanggang . , through his study of Toba Batak pariban marriages in Jambi, provides reasons that some Batak people do not agree to marry pariban for fear of loosening the bond between the two partners' extended families. This condition was finally resolved by Rola's following affirmation. The next step is to inform the mangain plan to the husband's uncle . who wants to adopt a child before passing it on to bona bones and bona ni ari. The rorobot bone, as part of the wife's side, is also not left behind as a party that must be notified about the process of adopting this child. Those who had been informed of the mangain plans, including the dongan tubu . family friend or relativ. and the raja drug lord, were invited on adoption The drug lord is a figure in power because he is an elder in such a wide environment. This figure is equivalent to the current village head, but controls a wider area, even exceeding one sub-district area. Raja bius was invited as an illustration of the government's involvement in the events or traditions of its community members, in this case mangain. Government involvement in mangain today is different from the past. The Batak Toba community is generally seen forcing its members to marry fellow Batak according to the Dalihan Na Tolu kinship structure. The times, especially when they had migrated out of North Sumatra, made the Toba Batak people meet more people from other tribes outside the Batak. Mangain also shows that baoa and boru sileban must go through the mangain process in order to marry Toba Batak people. Mangain is actually more than that because it shows indirectly that Toba Batak society is not so dependent on the obligation to marry another Batak. The mangain process is present as a bridge for the Toba Batak people and other tribes to carry out marriages. This mixed marriage finally presents a new view that the Batak kinship system is starting to change because it adjusts to conditions or social factors that occur in the midst of the Batak group itself. Updates in the JEK. VOLUME 1. ISSUE 1 Batak kinship system show harmony with the opinion of Rivers . who sees various kinship forms as unique because they are adapted to the conditions or social factors around Rivers stated his opinion in order to refute the views of Morgan. McLennan, and Kroeber, who saw the kinship system as universal throughout the world . 4: 17, . The two people from different ethnicities who married ultimately implied an attitude of prioritizing the unity and integrity of the Indonesian nation, not just love for the Batak tradition Dalihan Na Tolu (Silalahi, 2. The Toba Batak people often use the concept of halak black when they are distinguishing themselves from non-Batak ethnic groups to describe the dimensions of solid psychological and social relationships among Batak people (Bruner in Ihromi, 2. Bruner demonstrates this concept with a situation in the gambier trade between two Batak people and brothers who live in the same village (Bruner in Ritonga, 2. Both of them can compete healthily without conflict because of the mindset that separates the world of work from the brotherhood. The concept of halak hita does not apply if trade competition occurs between Batak people and non-Batak people and even leads to uncontrolled competition (Bruner in Ihromi, 2. Mangain also seems to show how the Batak people still pay attention to the concept of halak hita because they invite people who are not Batak to join the Batak kinship. Mangain, again as I explained before, paved the way for the Batak people to build solid relationships with non-Batak The solid relationship between unity and oneness can also be seen from the fact that the mangain tradition does not let go of the adopted child's relationship with his biological This situation is especially evident in the process of manipulating the body of a magodang which is intended for marriage. According to Rola's statement, several families who carry out the mangain process even give ulos to the families of the children they adopt during the mangain process. Giving ulos is considered a form of love that will start a good relationship between the two families in the future even though Rola said. Love can also be seen when the biological family of the adopted child is included in every Toba Batak custom after mangain. Participation can be seen starting from the time of their child's marriage to the Batak people according to Batak Toba custom, then the baptism of the childAiespecially for ChristiansAiuntil one day one of the parties in a kinship dies. Conclusions Traditions occur due to circumstances and eventually continue to be maintained from generation to generation to answer problems that occur over time. Mangain is an example. Indonesia, with its diversity, ironically presents conflicts that occur as a result of unfair stereotypes against various traditions and cultures. I saw the dividing walls between various tribes that have been formed since the past, even up to now, due to political interestsAithe struggle for resources. The mangain tradition, on the other hand, exists to unite the Indonesian nation. This statement was made directly by my informant. Several groups in Indonesia still have an attitude of ethnocentrism, even Sidauruk . argues that the Toba Batak community is one of them due to the presence of the mangain tradition. The Toba Batak still hold Dalihan Na Tolu as a way of life so their solidarity is thick enough to this day which is what I felt directly when looking for the right informants for the topic of this paper. My family is part of an association containing people with the surname Sihaloho in the Jakarta. Bogor. Depok. Tangerang, and Bekasi areas because my father's surname is Sihaloho. Daniel and his family are also part of this Sihaloho association so my family, especially Mawarida and (Al. Sudin, know Daniel's family, and vice versa. I knew Daniel when Mawarida told me about the right informants for this research because Mawarida still knew Daniel as someone who was an expert on adat in the Sihaloho clan association. I contacted (Al. Ferdinand first to put me in touch with Daniel because Mawarida didn't save Daniel and their family's phone numbers anymore. (The lat. Ferdinand also knew Daniel because he was part of the Sihaloho clan association. meeting with Daniel began with Daniel's story about . he lat. Sudin. Writing this paper, with all the ways that led me to finish it, for me is a reflection of how . he lat. Sudin was still alive even though his body was gone. This reflection also JEK. VOLUME 1. ISSUE 1 illustrates how the ideal relationship for the Toba Batak holdsDalihan Na Toluas as a guide for life. The picture in question is one of the social groups withinDalihan Na Tolu, that is manat mardongan tubu, which has been described at the beginning of the study of mangain. Mangainin fact, it shows a mutually supporting relationship between the Toba Batak extended family and people from other tribes who have received the Batak clan, along with their extended family. The relationship that implies solidarity is manifested in mutuality of being that happened from the process to the life after mangain. They are united also because of tradition mangain does not let go of the child's relationship with his biological family. So, do we still see unity only for "the same" fellow human beings? This question is still in the context of the entity that I ask as material for reflection on myself. Draft which was alluded to earlier was questioned again when religion and belief are also held by every human being to guide their own lives. This problem is described by (Ritonga, 2. through the conflict between Muslim and Christian Toba Bataks in Gajah Sakti. Asahan. North Sumatra. Funding This research received no external funding. Ethical Review Board Statement Not applicable. Informed Consent Statement Not applicable. Data Availability Statement Data will be available by special request. Conflicts of Interest The authors declare no conflict of interest. References