This article investigates the impact of transnational labor migration on agriculture in urbanizing communities in Bolivia. Previous research shows that the characteristics of rural out-migration communities affect whether agricultural practices are intensified and improved. Using a mixed methods approach, two closely located peri-urban communities with distinct prerequisites for agricultural development are analyzed. This study shows weak migration-induced changes in agriculture and concludes that transnational migration does not necessarily accelerate an ongoing urbanization process. It shows that remittances function to maintain farming for subsistence and as a secondary livelihood activity. However, major investments in agricultural intensification are not attractive due to the communities’ proximity to the main cities. This article highlights the need for nuanced conceptualization when studying migration-driven agricultural change in hybrid peri-urban spaces. Throughout Latin America, agricultural workers are increasingly seeking new opportunities through transnational migration. At the same time, hybrid peri-urban land use combining farming with non-farm livelihoods has become an important component of food security in growing Latin American cities. This mixed methods research investigates how transnational labor migration is affecting agricultural practices and land use through an investigation of two peri-urban communities in the high-altitude, grain-producing region outside the city of Sacaba in Cochabamba, Bolivia Fig. . Two majAltiplano, the Bolivian high plateau. This migration drove the population of the metropolitan zone of Cochabamba to increase from 0.5 to 1.2 million between 1992 and 2009. Since the mid-twentieth century, Cochabamban people have been migrating transnationally, mostly to Argentina and the USA, while Spain, Italy, and Brazil became important destination countries in the early 2000s  households’ involvement in agriculture and other livelihood activities in López Rancho and Molino Blanco; (2) agricultural land use with poor irrigation, weak local governance, and uncontrolled in-migration in López Rancho; (3) agricultural land use with abundant irrigation, efficient local governance, and controlled in-migration in Molino Blanco; and (4) the impacts of transnational migration on agricultural productivity in López Rancho and Molino Blanco. The concluding discussion addresses the theme of migration-induced agricultural change in the studied peri-urban communities. On the one hand, migration may result in labor loss, which can be compensated for by adopting labor-saving farming practices. On the other hand, monetary and social remittances may be key to making improvements in farming techniques.The new economics of labor migration theory proposes that migration is a household-level income diversification strategy to reduce economic risks . Both in López Rancho and Molino Blanco, there is also an ongoing process of minifundization, i.e., land fragmentation because of inheritance. Most of the agricultural households own only 1.5 ha land or less, which makes it difficult to engage in farming as the main economic activity . Moreover, according to several study participants, the lack of local non-farm employment opportunities drives their household members to migrate transnationally. “If you do not go abroad, there is not much to do here in the countryside; it is very difficult” . “My children are working in Argentina as there is no work here” .In López Rancho and Molino Blanco, typical off-farm employment includes working on nearby chicken farms and day labor for other farmers, such as plowing with oxen. The most common non-farm occupations include working as a taxi driver, bricklayer, and store clerk. Non-farm working opportunities, including transnational labor migration, are sought to supplement farm income, which can be an unstable income source and extremely demanding. “I was working as a cook in Spain almost for 10 years and I wanted to stay there as it is hard to work here; you need to irrigate, you need to Whereas the villagers of López Rancho and Molino Blanco have primarily been migrating to Argentina and Spain, some residents have also moved to Chile, Italy, the USA, and Israel. Both men and women migrate, but in this study, I do not particularly investigate the gender aspect of migration and migration-related agricultural change. While men mostly work as bricklayers abroad, women are often employed in elderly care and cleaning occupations in Spain and as vegetable sellers and seamstresses in Argentina. Although the migrants originate from agricultural households, they do not normally engage in agricultural employment abroad.Both in López Rancho and Molino Blanco, it is common for children to study and/or aspire to other forms of employment instead of continuing with farming, as presented in the following quotations. “I only work with farming as my children do not want to work in agriculture, brute work they tell me, and of course, it is brute work; they do not want to live in this way” . “No, my children do not want to continue with farming; they only grab their books and they have hardly been doing any agricultural work during this holiday. They only helped me a bit, to plant onions, but nothing else” . In other interviewed households of López Rancho and Molino Blanco, however, some children and young adults are still interested in farming at least as a part-time activity. “I do not have other plans than continuing with agriculture. I would like to own land, but I do not have enough money to buy it” . “My son works as a bricklayer, but he also grows potatoes and peas for subsistence” . “My four sons have been studying; one of them is working as a soldier in Santa Cruz, and another one is an electrician, and my three daughters who have not been studying are continuing with agricultural activities” .I was thinking about taking a bank loan and starting a business, but it is also difficult, as you might go bankrupt and then, the bank would take away your house. So, I will continue working with agriculture. As my children have other employment, they can pay for their clothing and groceries. So, farming is only to make my living .However, agriculture is considered by some villagers to be a traditional livelihood that cannot be abandoned, even though households have alternative sources of income. For instance, one informant with employment as a bricklayer shared that his father still insists on continuing to farm at the age of 71 even though the household can support itself by relying only on non-farm income. To conclude, agriculture remains an important livelihood activity in López Rancho and Molino Blanco despite the emerging urbanization process and households’ attempts to seek out other sources of income.While starting a small business or out-migrating transnationally is not always possible due to a lack of economic resources, there might also be a fear of losing everything due to failing to repay a bank loan. Hence, as also shown in the quotation below, farming can be viewed as the only available and feasible economic activity, especially by those of the elder generation, even though their children, often obtaining a higher educational level, might prefer other forms of employment.López Rancho is a community in which there is poor irrigation for agricultural land, weak governance of community resources, and uncontrolled in-migration. There are 400 affiliated households in López Rancho, and in general, based on the interviews and observations, the villagers’ socioeconomic status is lower than in Molino Blanco. For instance, the inhabitants have lower access to bathrooms and safe drinking water than in Molino Blanco Marañon . While tAsociación de Regantes de Apaka Punta (ARAP), an irrigation association governed by Molino Blanco and other upstream communities .Due to this recent division and the groups’ different interests, it is difficult to agree on any local legislation governing the available water and land resources. Because of the lack of regulation, the urbanization process is accelerating further and there have been problems of illegal acquisition of uncultivated land for housing purposes. The study participants also admit that agricultural households of López Rancho occasionally need to sell their farming land for housing because of the diminished production in recent years.In López Rancho, internal in-migration has been rapidly growing since 2010/2011. This urbanization process is evident when comparing the satellite images from 2006 to 2016 Fig. , and theBased on the output of remotely sensed data, to date, the recent urbanization process has had a somewhat limited impact on the total extent of agricultural land in López Rancho. While the mean area of individual fields has decreased by 15% due to land fragmentation, there was only a 3% decrease in the total field area from 1983 to 2013 .Hence, it is possible to harvest potatoes and flowers twice per year in Molino Blanco.Since colonial times, the agricultural fields of Molino Blanco have been irrigated through an advanced canal system that utilizes water originating from nearby mountain reservoirs. In 1998, the canal system was improved and Achocalla, the principal reservoir, was extended to accommodate more water. ARAP, the well-organized irrigation association governing water resources, was established the same year. There are 27 member communities in the association, and these syndicates receive water from different reservoirs. As Molino Blanco is one of the main shareholders and a founding member, the syndicate is connected to several water reservoirs. The local irrigation syndicate of Molino Blanco distributes water according to the size of community members’ agricultural land, and the associated farmers pay a monthly fee for their water use. Although the farmers claim that precipitation has been decreasing and temperatures have been increasing over the course of recent years, there is no lack of water due to the irrigation system in the community, as described below.Becoming affiliated in the neighboring communities is cheap, BOB 500 [USD ~72], whereas it costs BOB 5,000 [USD ~722] here [in Molino Blanco]. And the fee will be raised to BOB 15,000 . For inheritors of the villagers, it is BOB 500 [USD ~72] .As stated above, the affiliation fee for families who are not inheritors of the original villagers is ten times the affiliation fees in other nearby communities, including López Rancho. In addition, community members are planning to triple the fee.In comparison to López Rancho, the process of internal in-migration is strictly limited in Molino Blanco. As the community members form a more unified group of peasants, it has been possible to reach a consensus on local policies governing the water and land resources. Land sales are controlled by high affiliation fees that new community members are required to pay to become enrolled in the community and to get access to basic services. Thus, in-migrants from underprivileged regions of Bolivia cannot afford to live in Molino Blanco.2 smaller than in López Rancho in 2013 .In addition to the house construction on inherited land, some informants mentioned that the community’s rural image is starting to be hampered because of occasional land sales for housing purposes.The villagers want Molino Blanco to be a rural place, but they also sell land for house construction. For instance, they sell land to outsiders when they get sick if there are no other villagers who would like to buy. They are building houses down there; I think it is a lawyer [who bought the land] .Returning migrants from Spain and other countries have bought land here to build their house in this village. I have asked why they buy land here, and they tell me, “It is a paradise here.” But, if we fill it up with cement, it is not going to remain a paradise .Accordingly, as demonstrated in the quotations above, land for housing purposes is increasingly bought by families with access to economic resources. Due to these families’ higher socioeconomic status, it is clearly not possible to thwart their intention to purchase land by requiring high affiliation fees for community membership. Nevertheless, as opposed to López Rancho, urbanization through in-migration is still heavily controlled in Molino Blanco, and some of the new community members also practice farming.Aerial photographs and high-resolution satellite images of agricultural fields show that the total area of cultivated land in Molino Blanco increased by 2% from 1983 to 2013. The mean area of individual fields decreased by 18% and was 242.1 mWe also cultivated when I was working in Spain for a period of almost 10 years but not as much as before. During that period, we only cultivated alfalfa for the cattle, as it is easier to take care of. You only need to irrigate, and you just leave it to grow for eight years or more. However, it does not give you any money; the cows eat it all. My mother and my sister worked with that when my husband and I were in Spain .While most of the migrant households receive monetary remittances regularly or sporadically, the money is mainly used for everyday consumption and to finance studies, house construction, and the expenses of left-behind children. However, as demonstrated below, several study participants report occasionally using remittances to purchase seeds, pesticides, fertilizers, irrigation water, and services of tractor or oxen-driven plowing or to hire agricultural labor for certain tasks, such as planting and harvesting. “We buy seeds ” . “We have also invested remittances in agriculture [in addition to buying a house in the city of Sacaba], as you need quite a lot of capital to hire tractors and [to hire workers] for harvesting” .Despite the loss of labor due to transnational migration, most families continue to farm. Both in López Rancho and Molino Blanco, several study participants mention that it has become difficult to hire laborers, as many working-age residents have been out-migrating or subsisting on non-farm employment. “There is no manpower as some people have become taxi drivers, some people have moved to other regions, and then other people have traveled to Santa Cruz or also abroad, so there are no people to work [in agriculture]” . Instead of hiring other villagers, the farmers often need to search for laborers originating from other communities. “We need to be looking for workers; we normally go to the main road to bring them” . If the households cannot find any available laborers, they do agricultural work themselves or extensify land use. To compensate for the labor shortages when working-age household members are abroad, families will cultivate only part of their land or switch to alfalfa cultivation for livestock. The following quotation shows how a migrant household adjusted its workload.chicha, and once he’s drunk, he does not want to work anymore. It is therefore faster to plow with a tractor, as tractor drivers drink only soda” .In fact, several study participants admit that it is not profitable to invest quantities of remittances in farming because of insufficient irrigation water in López Rancho and land shortage in Molino Blanco. “There is [cultivable] land available here that we would like to buy [with remittances], but we cannot because we do not have water” . “Most of the used farming techniques are still manual, and it is only with certain crops, like wheat, that we use a combination of tractor and manual labor” . “Because of small plot sizes, it is not even possible to industrialize our agricultural production” . As demonstrated by these quotations, there is very little evidence that remittances have resulted in higher agricultural productivity in López Rancho and Molino Blanco through investments in farming land, new methods, and equipment. Thus, non-migrant households and migrant households normally use the same traditional farming methods, even if the latter often have better economic possibilities to improve agricultural practices. Nevertheless, remittances have contributed to a minor increase in tractor use instead of oxen. It is more expensive to hire a tractor by the hour but as seen in the following quotation, it often turns out to be a more time and cost efficient to use such a plowing service than to use oxen. “When using oxen, the plowman drinks A few migrant households have used remittances to buy agricultural land in nearby communities and in the department of Santa Cruz. “My brother [who was working as a construction worker in Spain] has bought two pieces of [agricultural] land in Santa Cruz” . “My mother [who is employed as an elderly care worker in Spain] is thinking of buying a farm in Santa Cruz to raise cattle and to grow fruits” . As shown by these quotations, migrant households with access to remittances are also looking for possibilities to invest in farming land in other locations in Bolivia. In contrast to both communities studied here, there is plenty of fertile farming land available in Santa Cruz, enabling a profitable livelihood, for instance, through raising cattle.Cut flower production is economically much better than other traditionally cultivated crops, but it requires a lot of investment. First, you need to have a drilled well since, without water, it is not possible to do anything. Then, if you have a greenhouse, you can produce anything. Without a greenhouse, you just seed in vain, as the moisture and the heat paralyze your plants. If we had not gone to Spain, it would have been completely impossible for us to achieve this kind of cut flower production .As the quotation above shows, monetary remittances enabled investment in cash-intensive agricultural production that is otherwise not common in Sacaba. Although cut flowers are cultivated in López Rancho and Molino Blanco, the other famers do not produce them in such a commercialized manner in greenhouses. In addition to monetary remittances, out-migration in some cases increases knowledge of new kinds of crops through social remittances, as presented in the following quotation.I also have green beans [growing in my garden]; they sent me the seeds from Spain. One of my sons lives there. And my wife’s daughter lives in Rome in Italy, and her sister lives in Milan, and they brought us carrot seeds in a small envelope, and white onion seeds as well .These two examples provide an exception to the overall result of minimal migration-related changes in farming practices and land use. As opposed to most migrant families in López Rancho and Molino Blanco, these two households have family members who have been studying agronomy or who otherwise have detailed knowledge of different farming techniques, including their advantages and disadvantages.Although migration-driven changes to agriculture are generally limited to extensification in both López Rancho and Molino Blanco, there are a few exceptions. For instance, a couple residing in López Rancho worked for 6 years in Spain and used remittances to introduce cut flower cultivation in greenhouses.The findings of this study do not support previous investigations that suggest that labor migration results in the abandonment of agricultural land (see Aide and Grau Nor do the results of this investigation show migration-driven intensification and commercialization of agriculture, as reported in other studies (see, e.g., de Haas ayllu organization … built upon a foundation of kinship and reciprocity, communal land tenure, and ecological complementarity” (Beaule As shown in several previous studies, agriculture has generally become a secondary livelihood as the households of López Rancho and Molino Blanco have gained access to other income sources through off-farm/non-farm employment and labor migration (see also Black ” Beaule , p. 605 ” Beaule . I argueUnlike previous studies, this investigation does not identify any clear patterns of community-specific migration-induced farming practices depending on the agricultural community’s suitability for agricultural development (cf. Aguilar-Støen et al. In conclusion, the results of this investigation are consistent with studies that show weak and mixed impacts of transnational labor migration on agriculture cf. Gray . This st


Use of big data is becoming increasingly popular in medical research. Since big data-based projects differ notably from classical research studies, both in terms of scope and quality, a debate is apt as to whether big data require new approaches to scientific reasoning different from those established in statistics and philosophy of science.The progressing digitalization of our societies generates vast amounts of data that also become available for medical research. Here, the big promise of big data is to facilitate major improvements in the treatment, diagnosis and prevention of diseases. An ongoing examination of the idiosyncrasies of big data is therefore essential to ensure that the field stays congruent with the principles of evidence-based medicine. We discuss the inherent challenges and opportunities of big data in medicine from a methodological point of view, particularly highlighting the relative importance of causality and correlation in commercial and medical research settings. We make a strong case for upholding the distinction between exploratory data analysis facilitating hypothesis generation and confirmatory approaches involving hypothesis validation. An independent verification of research results will be ever more important in the context of big data, where data quality is often hampered by a lack of standardization and structuring.We argue that it would be both unnecessary and dangerous to discard long-established principles of data generation, analysis and interpretation in the age of big data. While many medical research areas may reasonably benefit from big data analyses, they should nevertheless be complemented by carefully designed (prospective) studies. The progressing digitalization of our societies generates vast amounts of data that are also made available for secondary, mostly opportunistic, use by third parties. Already in the late 1990s, the term ‘big data’ was coined for this type of “high-volume, high-velocity and/or high-variety information assets that demand cost-effective, innovative forms of information processing that enable enhanced insight, decision making, and process automation”  when effect sizes are smaller; when there is a greater number and lesser preselection of tested relationships; where there is greater flexibility in designs, definitions, outcomes, and analytical modes” . UndoubtPopper highlighted that, for a hypothesis to count as scientific, it must be falsifiable . His vieTo test universal hypotheses, researchers must design studies that render falsification possible or, even better, likely Fig. . The cha“Correlation supersedes causation”  is one oThe above notwithstanding, it is safe to say that the majority view in medical research ranks causality more important than correlation. In the words of Pearl , “most sCausality cannot be inferred from observational data alone but requires additional information or knowledge. From a purist point of view, only “discovering an underlying mechanism proves the truth of the causal hypothesis in question” . It shouImage analysis plays an important role in medical research where computer and magnetic resonance tomography scans, for example, easily qualify as big data, at least in terms of volume and velocity . However, while processing of single images is an interesting research subject in its own right, particularly with a view to the use of machine learning and artificial intelligence techniques, the medically relevant content of an image often manifests at much lower levels of complexity. In the end, an image may comprise myriads of pixels, but is still one ‘measurement’. For instance, the task of classifying a mammogram as ‘tumour present’ or ‘tumour absent’ may require complex and computationally challenging algorithms, but the resulting diagnosis is essentially binary. Thus, inference making via medical image analysis may well draw upon big data, but most often it does not represent big data analysis sensu stricto.In other research areas, particularly in clinical medicine, epidemiology and public health, big data are only of low to moderate quality because they are observational, uncontrolled, and only seemingly complete, of mixed origin and were not specifically collected for research purposes. In the context of biomedical research, Leonelli  identifiFor big data, the famous idiom “garbage in, garbage out” may easily worsen to “big garbage in, big garbage out”. Data quality is an issue in medical research because of a frequent lack of standardization and structuring. Hence, any sensible use of big data in medical research critically depends upon the extent to which these data are ‘good data’ in the sense that everything possible has been done to sustain their quality. A fourth letter V was therefore proposed as an amendment of the three Vs of big data. The fourth V stands for veracity and for the challenge to ensure adequate care and diligence in big data analyses . It is aNature commentary entitled “Personalized medicine: Time for one-person trials”. His views reflected the author’s particular professional interest in genomics, where millions of DNA variants are assessed in individual patients. However, it is a wide-spread albeit unfortunate misunderstanding that such ‘in-depth’ investigations of small samples ever lead to generalizable results. Instead, they should be deferred to the realm of case studies. The latter, however, are known to represent a low evidence level only and therefore have confined themselves mostly to hypothesis generation since the advent of evidence-based medicine in the 1990s.It seems paradoxical at first glance to regard insufficient sample size as a potential problem of big data. However, ‘big data’ often refers to large numbers of attributes but not necessarily to large numbers of independent observations of these attributes. In most commercial applications, such a limitation does not play a role because the data in question are gathered opportunistically from thousands of people anyway, usually as a by-product of internet-based services. In medical research, however, big data may comprise millions of attributes measured in a few patients, typically with the aim to provide them with ‘personalized medicine’. Schork  advocateAccording to Kuhn , a paradNature Genetics, of so-called ‘polygenic risk scores’ (PRS). PRS are distilled from the summary statistics of large-scale genetic studies of common human disorders, in this case type 2 diabetes, coronary artery disease, inflammatory bowel disease, atrial fibrillation and breast cancer. Even though none of the scores was properly validated, neither prospectively nor by drawing upon existing long-term studies, and despite their obvious lack of predictive power [That our considerations are not just mind games is exemplified by a much-noticed recent study by Khera et al. , publishve power , clinicave power  and by ove power .In summary, we are adamant that obviating diligence and thoroughness in medical research with big data is a prospect that is apocalyptic, rather than paradisiac, and we would be wise to avoid it.


Everywhere there are children, there are screens, and child–computer interaction is ubiquitous. Despite their omnipresence, research on the impact of screens on children’s learning lags behind the development of digital tools. Apple’s App Store has an abundance of “educational” apps, but many of these apps’ claims are unsubstantiated. Organizations responsible for vetting quality products for young people, such as the American Library Association, are developing resources to help identify the best digital products available, but they remain difficult to find, and there is limited guidance for app designers when it comes to designing apps for younger audiences. Our interdisciplinary, empirical study was inspired by “co-creation”  and “coo The term “Digitods…” according In fact, determining what constitutes “quality” within an app is up for debate. It is easier to determine what constitutes a lack of quality—for example, apps that feature in-app advertising, have poor navigation, feature distracting and non-educational gamified elements, or those that infringe upon children’s privacy. To explore what constitutes “quality” within a digital product for young children, we decided to create an app that addresses a fundamental literacy need of preliterate children, between the ages of 3-to-6-years-old—learning to identify and write the alphabet. We had three goals. First, our app would be high quality. We used librarian Claudia Haines’ rubric called Evaluating Apps and New Media for Young Children  and KIDMLearning to recognize and write letters, which is a foundational building block in developing literacy, is an onerous process. We sought to explore verbs for two reasons. First, the touchscreen interface allows for demonstrative animation and incorporates motion design to explain the definition of a word. Second, because existing resources, such as alphabet apps and books tend to focus on nouns, and research, as cited above, points to a lack of focus on verbs, we saw an opportunity for our app to fill a void and tackle a difficult concept for young audiences. By focusing on verbs, our app seeks to expand children’s vocabulary acquisition, especially around their understanding of verbs, as well as their letter writing skills.Our article begins with a review of the literature that addresses: (1) the ubiquitous nature of technology for young children; (2) conflicting views on the use of technology with this population; (3) the role of parents in selecting and determining use; (4) children’s letter learning in multimodal formats; and (5) app evaluation and guidelines for developers. Next, we discuss our methodology and our user studies, which is followed by our research questions and findings.“Digital technologies are the new tools—mediating a child’s experience of the world, their language, their physical interactions through cause and effect, and their social interactions. Technology has also become an integral part of many informal learning environments that children encounter more and more often in their lives” , p. 27.According to Common Sense Media’s 2017 study, the use of mobile technologies is widespread. Unfortunately, most of the apps under the “educational” category in the App Store target only rote academic skills, are not based on established curricula, and use little or no input from developmental specialists or educators. According to Experts and parents have conflicting views on the use of digital tools with young children. The American Association of Pediatrics (AAP) has gone from a 2012 recommendation of zero screen time for children under the age of two, to a gradual acceptance with limitations in 2016—in part because parents are using these tools with their young children. As The AAP released a revised policy on screen time in 2016, which softened their original stance and advised pediatricians to counsel parents on developing a Family Media Use Plan that features “unplugged spaces and times in their homes,” using technology in “social and creative ways,” and balancing technology with “sleep, exercise, play, reading aloud, and social interactions” , p. 3. Thow media is used rather than how often. No matter what agencies, such as the AAP recommend, the reality is that “[t]he socio-cultural environment of the current population supports technology use by younger children”  framework” , p. 5. WDespite recommendations of limiting screen time with young children, it is easy to understand parental anxiety due to the early adoption of touchscreen technology that occurs in formal education. Researchers such as According to Schickedanz discusses the importance of print in all its forms, from environmental print to books to children’s own writing. In a later book, co-authored by The Teacher’s Manual for Phonological Awareness Literacy Screening (PALS) carried out by the majority of schools in Virginia discusses several criteria on which to test preschool children on their pre-literacy skills. Developed for Virginia’s Early Intervention Reading Initiative, PALS allows schools to assess children in order to better design literacy instruction and provide support to those who need it. According to PALS-PreK, a set of skills which are “predictive of future reading success” , para. 1Research shows that technology can be beneficial in developing young children’s handwriting skills. “Research provides many suggestions for those who create and design educational apps for children. In a broad sense, “The best design for children considers their developmental stages when creating classification schemes, hierarchies, metadata, and interfaces” , p. 159.“… games should: (1) [include] developmentally appropriate content; (2) integrate the theoretical frameworks from the learning science field; (3) embed learning in socially rich contexts; (4) develop diverse content; and (5) create a balance between play and real-world learning opportunities. We build the principles around a hypothetical educational game designed to facilitate language development” , p. 314.The Libraries are key sites for providing access to technology and teaching digital literacy and skills. co-operative inquiry (co-creation methodology (2008). Co-operative inquiry isOur child-centered design methodology borrows from Allison Druin’s  inquiry , 2002 an“…grounded in human-computer interaction (HCI) research and theories of cooperative design [3], participatory design [4], contextual inquiry [5], activity theory [6], and situated action [7]. Cooperative Inquiry is unique from these previous design methods in that it is specifically intended to inform the design process of teams that include adults and children” , p. 14.According to While ideally, diversity should encompass children of different ethnic and racial groups, socio-economic levels, abilities, and genders, because of the small size of our study, diversity here is limited to diversity of age, gender, and race. Generally, working with children presents challenges. “(O)ften there is a gap between the contributions from young design partners and the realities of designing a technological artifact” , p. 2377Our process included three studies, of which the first two involved co-design activities with children: a prototype study (User Study 1), a redesigned prototype study (User Study 2), and a focus group with preschool and kindergarten teachers (Teacher Focus Group). All three studies incorporated free play time and an interview period. As However, we cautiously interpret our findings, as our measures were qualitative in nature and may not translate to other settings.This first study involved testing the rough prototype. The process began with testing a brand-new typeface, designed by Aoife Mooney (which we later did not use). In order to design an alphabet, type designers begin with five letters: A, D, H, K, and M, as those letters include all the modular strokes needed to create all upper case letters in the alphabet. In addition, these letters accurately portray most movements a child would need in order to practice the alphabet within our app. At the time of our first study, the interface design was complete but only those first five letters had been programmed to unlock an animation reward. The other 21 letters led back to the main menu. The interface was operating on one iPad mini, one iPad 2 and several 3rd and 4th generation iPads. Our goal was to test the interface, the typeface and then respond to the feedback. By focusing on this limited user study we gained early and definitive feedback, which allowed for quick refinement, without impacting our budget or timeline. This tactic is often used in user experience design, when valuable information can be collected with a limited design prototype and will enable for product development to respond and refine.Our study included the following steps:(1)Children had free play with the app;(2)Two researchers conducted one-on-one interviews with children and caregivers;(3)Children worked on a paper prototyping exercise Co-design activity: children made suggestions for improvements to the app on iPad-shaped sketch paper;(5)Researchers conducted a follow-up interview with the children to gather their suggestions.During the session, data was gathered as follows: (1) a doctoral student took ethnographic field notes ; (2) theAfter free play time, children worked with the team using the paper prototype interface. This relatively inexpensive activity served as a hands-on approach to assess the typography to be used in the app and to test the user interface without updating the development, as shown in Figure Lastly, children participated in a co-design activity in which they were provided with iPad-shaped paper and asked to sketch the animated reward they would want to see for successfully writing a letter Figure .Our interview notes, ethnographic field notes, photographs, and observation of the children provided feedback on how they used the interface and responded to the reward videos. Since the sample size of our first user study was very small, we did not calculate inter-rater reliability, and subsequently, our results are limited and not generalizable.We used Google Sheets (shared only between the researchers) for our analysis, logging results from the interviews, prototype testing, and our observations. The ethnographic fieldnotes added further details and confirmed findings. In addition to verbal responses, children’s notes and sketches on paper prototypes provided suggestions for improvements. In future larger studies, we will include measures of inter-rater agreement. While we used photographs in this study, we did not video record the children, which we would do in a future study.There were three findings from the first study:(1)Our prototype needed to be reconfigured;(2)The typeface needed to be reconsidered; and(3)Our users needed error feedback.While the youngest children were interested in the app, it was a challenge to work with them. For example, one 4-year-old boy repeatedly got up and walked away saying “I’ll be right back, Mommy.” Another was more interested in the many entertaining objects  in the children’s library center where we did the study; and another would not speak directly to the interviewer, but only to her mother. Overall, shyness was a big factor with younger children, who struggled to provide feedback—especially negative feedback. Compared to the younger group, the older children were more easily focused, easily able to vocalize their criticisms, and were visibly delighted to be included in the process based on their vocal and abundant feedback.Despite the technical and typographic difficulties, our young users remained engaged in playing with the Energetic Alpha app. Other researchers have found the same in similar studies such as The typeface was an immediate concern even before the study began. Initially, we chose a slab serif typeface that was fun and playful, but unfortunately, the more complicated shapes meant that our young and preliterate audience did not recognize some of the letters. The youngest users were not yet ready to compare and understand the relationship between letters with serifs and those without (san serifs). Furthermore, as a tracing guide for handwriting, serif letterforms were confusing. Both younger and older children would fill in the extra serif slabs at the end of the letters. The paper prototyping demonstrated that we needed to change our typeface to a simpler sans-serif font.Finally, children in both age groups became frustrated when they made errors or had to correct their stroke order. Here is an example from a 6-year-old girl:When … she couldn’t get the letter to trace correctly, she said, “This is annoying me” over and over and made a surprised face. She slowed down and tried to be precise, but it still didn’t work. “I already did it.” When she finished it, [researcher] asked, “What happened?’ She said, “I don’t know. Now what do I do?” Then she made some funny faces and said, “I’m frustrated” .It was evident that we needed to build error feedback into our next design iteration. In addition, neither group of children (younger or older) were sure where to begin writing letters. An 11-year-old girl provided the following feedback: “I don’t think that [younger] kids will understand that they have to follow the red dots – they will think they can do it their own way” . We realized we needed to insert a visual cue that would signal where to begin making marks.We found that the animations held the attention of all users. Even when they did not like an animation, as reported in the final question and answer session, they finished watching until the end of the sequence Figure . When weIt took several months to redesign the application. We began by reconfiguring the programming in the app’s backend and developed a new prototype with a simpler iOS programming method. We also chose to host the animations online, which made the app size smaller and within the iOS guidelines. While this decision contradicts Our team selected a new typeface, ABeZeh, designed by Anja Meiners of bBox Type, which is a foundry located in Berlin, Germany Figure . ABeZeh To provide error feedback, our team used motion design and sound elements. After User Study 1, we integrated a trace hint animation that played at two moments: (1) when a child attempts to write a letter in the wrong stroke order or (2) when a child waits on the screen and does not begin the action of writing a particular letter Figure . At thisA variety of motion design animation strategies were used to test which one the children preferred including stop motion, time lapse, vector animations, hand-drawn cell animations, and traditional video recording. We created six additional animations for the letters B, C, F, P, S, and X. Our goal was to use various motion design strategies as a means to appeal to multiple user groups.The second user study included five children aged 4–6 and nine children aged 7–11. The children were interviewed individually or in family groups. There were also three researchers, one research assistant taking notes and a photographer. We used task booklets to guide the interview session No sound or animation;(2)No animation but with sound; and(3)Sound and animation fully integrated.Users had an opportunity to define their preferences for interface sounds (success and error feedback sounds). We provided them with an HTML website on which we pushed buttons to play a range of sounds. On the task booklet, we circled their preferences and placed an “X” over sounds they did not like.We asked the participants about their preferences after they viewed all of the finished animations  Figure . We provWe finished the study by asking the children whether they enjoyed the app and if they would recommend it to a friend. The questions had answers that were based on a child-friendly Likert scale and allowed for a range of answers to be shared Figure .We found that children required concrete feedback scenarios that utilized sound to accurately self-correct. When we conducted the test without sound, the children were not as quick to understand the interface or to figure out how to self-correct stroke order errors. Sound as an element is always an important feature in interface design, but we found it especially helpful for our preliterate learners. A buzzer provided feedback that was irritating to some children but immediately told the user they needed to self-correct in the same way an adult working one-on-one with a child practicing letter-writing might correct them with verbal commands and gestures.We also discovered that concrete feedback in the form of visual cues played an important role. Upon testing the new prototype, we realized that the addition of sound and trace hint animations made it easier for children to understand the required tasks, to determine how to navigate the interface, and provided a much better user experience than one without these elements.In addition to being entertaining, animation can also provide motivation and engagement for young learners that can extend the learning experience beyond skill building and into the reward-experience. We were not surprised to find that pairing animations with letterforms provided strong motivation to continue using the app, and essentially, practice letter writing. Users were still engaged with the animation rewards and continued wanting to discover more even after they had watched all of the completed animations. It was also interesting that children even watched animations they claimed not to like from beginning to end.Some children were interested in the stop-motion, whereas others were drawn to the vector-style animations. Since the design strategy was intended to be eclectic and allow children to sample new formats, it also permitted surprise and anticipation. While there was not a definitive answer for which animation style they preferred, we did find that children preferred longer animations with more narrative elements. The shorter animations, such as those for letters “K” and “X,” averaging about 10 s each, were the animations that children complained about. In general, children preferred longer animations that averaged 30 s to 2 min. Shorter animations (8–10 s) were considered “boring” or “disappointing.”Finally, there was much agreement among the children regarding sounds. To signal errors, we were using a loud, game-show-style buzzer. However, after hearing the children’s feedback, we quickly ruled this sound out; children found it to be an upsetting and distracting noise. Instead, they preferred a lower tone that had an electronic beat.We conducted a small focus group study of the app with two pre-kindergarten teachers and one kindergarten teacher at the University’s Child Development Center. Two researchers met the teachers in a conference room at the end of the day and after the children had left. Like the children, the teachers were able to experience free play with the app and explore the interface and animations. As the children had experienced in the first user study, the app crashed repeatedly and the teachers experienced a few stroke order errors. In many ways, this served as a short beta testing session. The teacher study confirmed the results from our first two studies. Like the children (described in the next section), teachers also saw a need for competition or success tracking. They suggested adding a feature that would let the child practice writing their name, and we hope to do this in the next version of the app. One teacher suggested a visual effect, like stars, to show the children how well they are doing. Teachers also critiqued the content choices of the animations. They felt that one of the first animations created for the app, “A is for abstract art,” was too complex for preschoolers and pointed out that art is a difficult word as preschoolers do not hear the “a” sound in “art” and only hear the “rt” sound. One teacher informed us that since handwriting is no longer part of school testing in the United States, many schools are choosing to make handwriting a low priority in the overall curriculum.We were able to utilize many of the children’s suggestions and feedback. The most interesting changes and suggestions came from our User Study 1, when we gathered children’s ideas for animations. Their feedback was very helpful in designing the remaining animations. For instance, one boy suggested we include a lion, and as a result, the animation for R became “R is for Roar” Figure . AnotherWe also found that the children wanted some competitive gameplay elements that would provide additional affirmation of success. One child suggested we use fireworks upon successful completion of a task, whereas another proposed a growing pile of apples to represent accomplishments. One child suggested adding a visual check mark along with a sound that would signify success and another suggested a “thumbs up.” An older child wanted to see a leader-board and gamified levels within the game, and suggested that different levels should unlock badges Figure . While tA success tracker in the right corner of the interface shows how many times a child has completed a letter. We also created incremental rewards for completing one stroke. After a child writes a letter, a star-burst appears along with a “ding” sound. When they complete a letter, they are rewarded with a video. If they are offline or have rewards turned off, then they get the “good job” rocket Figure .Finally, we integrated the results from the teacher study by addressing all of the technical issues and creating competitive play features as already described above, and the animations for A and S were redesigned according to the children’s suggestions.Our findings were limited by having a small number of users. Even though we created an inclusive app and included diverse children and adults in the app design and in our user studies, the researchers were all Caucasian. In future studies, researchers should also include a diverse group of scholars.It would also be useful to test children  using the app over longer time. This would allow us to see if, as children become familiar with the app and proficient in using it, they prefer shorter or longer videos, or at which point children become bored with the animations and seek variety. In addition, a future study might examine whether any letter writing fluency gained via using the app, translates to handwriting fluency in print.Writing proficiency is an important skill that begins with understanding how to read and write letters and form letters quickly. According to “If children cannot form letters—or cannot form them with reasonable legibility and speed – they cannot translate the language in their mind into the written text. Struggling with handwriting can lead to a self-fulfilling prophecy in which students avoid writing, and see themselves as not being able to able to write, and fall further behind their peers” (p. 20).Another limitation was having to rely on an Internet connection for the best user experience. While an initial goal of our project was to create an app that worked without an Internet connection, we found that programming 26 videos into the app exceeded the maximum size allowed by the App Store. While the app does work without Internet access, rewarding children with a rocket, rather than a video for correctly completing a letter, the gamified elements certainly work best when online.Our goal with this project was to create a digital letter writing tool for young children. Since we know that young children are interested in handheld devices, such as iPads and mobile screens, we sought to create a high-quality tool that combined simplified gamification with technology in order to make a monotonous task—letter writing practice—entertaining. Despite the fact that it is no longer emphasized in school, our teacher study showed that at least these teachers still believe that handwriting is important. We set three goals for our study: (1) to make a high-quality app; (2) to create an age-appropriate interface; and (3) to create an inclusive app for all children. By using This study was approved by Kent State University’s Institutional Review Board. The teachers and parents signed a consent form after reading an informational letter and discussing the research with the research team. The parents signed a consent form allowing their children to participate. This form included an audio, video and photography consent, along with a privacy and confidentiality form. The original form stated: “Identifiable information will not be made available in the publications and/or presentations of the research date. Due to this, we obtained additional photography permissions from children who are identifiable in this article. Parents were asked to provide written approval of having their child’s photographic image published in conjunction with this research. Parents of both children who are identifiable, approved and signed additional permission forms.”Doug Delahanty, IRB Chair, Kent State UniversityInstitutional Review BoardTricia Sloan, Administrator, Kent State UniversityInstitutional Review BoardKevin McCreary, Assistant Director, Kent State UniversityInstitutional Review BoardPaulette Washko, Director, Kent State UniversityInstitutional Review BoardMM is the lead author, led the initial research design, collaborated on co-design activities, and co-wrote and edited the article. GR is the app creator, designer and art director for the Energetic Alpha iPad App, She led co-design activities, and co-authored and edited the article. CA drafted the literature review, took extensive field notes during testing, and helped with copy-editing and proofreading.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.


In the 2008 article “A Review of Feral Cat Control,” Robertson explored the trend developing in the management of so-called “feral” cats away from lethal methods toward the non-lethal method of trap-neuter-return (TNR). The review explored various issues raised by the presence of these unowned, free-roaming cats in our neighborhoods , stakeholder interests, and management options—all based on then-available information. Missing from the review, however, was an exploration of the shifting ethics underlying TNR's increasing popularity. In this essay, we explore the ethical aspects of community cat management in the U.S. as reflected in the momentum of the “no-kill movement” generally and TNR in particular. We argue that these powerful cultural currents reflect two interrelated ethical theories: (1) a zoocentric ethic that recognizes the intrinsic value of non-human animals beyond any instrumental value to humans, and (2) a virtue ethic that recognizes the legitimacy of “emotional” considerations  that rightly accompany decisions about how best to manage community cats. In “A Review of Feral Cat Control,” Robertson  exploredIn the 10 years since the publication of Robertson's review, TNR has become more widely adopted in communities across the U.S. , though As Robertson  explaineThis shift from an anthropocentric ethic to a zoocentric ethic is, in part, the result of a growing body of research demonstrating cognition, emotion, and sentience in animals once assumed to be “unfeeling” and relegated to the lower rungs of the now-obsolete “evolutionary ladder” , 9. SentAccompanying this recognition of animals' intrinsic worth is a virtue ethic based neither on maximizing “the good”  nor an obligation to some duty . Instead, “virtue ethics focus on the character traits, or virtues, manifested in proper conduct… includ[ing] respect, humility, generosity, integrity, patience, and, of course, compassion” .The New York Times is reporting that Tahlequah, a 20-year-old female orca “has been swimming with her daughter's body through choppy seas… on what social media observers and orca researchers call a ‘tour of griefș ” . The success of this paradigm shift can also be seen in the compassionate conservation movement's guiding principle of “first do no harm” and “desire to eliminate unnecessary suffering and to prioritize animals as individuals, not just as species”  is further evidence of a shift toward a zoocentric virtue ethic that recognizes the intrinsic value of animals beyond any instrumental value to humans, and the considerable role that compassion and empathy play in our “animal control” preferences. This last point is worth highlighting since critics of TNR routinely dismiss its support by animal welfare organizations and the general public as an emotional, but ultimately misguided, response –37. As Rtoo rational, leaving no room for the legitimate role of emotions in ethical deliberation and underpinned by a mistaken view of what emotions are like” .“In my view, this approach is if anything Historically, the management of companion animals was driven largely by the same anthropocentric utilitarian ethical framework used by wildlife managers. As a result, lethal methods were used almost exclusively. As the animal rights movement of the 1970s and 1980s began to focus attention on the intrinsic value of all animals and their right to be treated with compassion , 7, the In 2007, a year before Robertson's review was published, Winograd  formaliz“For feral cats, TNR is the sole alternative to the mass killing perpetrated in U.S. animal shelters… In fact, because of their unsocial disposition, they are not considered adoption candidates. As a result, there is no other animal entering whose prospects are so grim and outcome so certain. Without TNR, all feral cats who enter shelters are killed” .The protections offered by these programs reflect our evolving ethics; the once-dominant anthropocentric utilitarian framework is being challenged by our recognition of the intrinsic value of cats  and the legitimacy of compassion in shaping our moral obligation to them.Although TNR is controversial , 45, 46,preferences. On the other hand, it's clear once again—from both surveys—that there's little public support for lethal management methods.Other surveys on the subject indicate lower levels of support for TNR; however, these apparent discrepancies are easily understood when the survey designs are scrutinized. Ash and Adams , for exaA survey of the general public in four Florida counties found that 54% of respondents preferred TNR, compared to 25% who preferred placement in a long-term no-kill shelter and 15% preferring to trap and “euthanize” cats , 54. RegOther surveys investigating public support for TNR have reported lethal methods to be more popular than non-lethal methods. Loyd and Miller , for exaSupport for TNR extends beyond the general public, too. The American Public Health Association's Veterinary Public Health Special Primary Interest Group, for example, “support[s] well-designed  nor oppose[d] appropriately managed cat colony programs” . And morSuch endorsements reflect the considerable and varied memberships of the individual organizations—and by extension, the public they serve. Again, such clear support for TNR reflects the growing consensus that community cats have intrinsic value and deserve to be treated with compassion.The momentum we're witnessing in the no-kill movement generally, and TNR in particular, reflect a profound shift away from an anthropocentric utilitarian ethical framework toward a zoocentric virtue-based ethical framework that recognizes the intrinsic value of animals beyond any instrumental value to humans and our moral obligation to treat them with compassion. Ten years ago, Robertson  highlighTNR's momentum and broad public support suggest almost an arc-of-history inevitability, and brings to mind a quote from Vucetich et al. : “AlthouBoth authors contributed equally to the overall development of this essay. PW contributed the majority of content related to public opinion surveys while JS contributed the majority of content related to various ethical philosophies.In recognition of Frontiers' policy and our ethical obligations as authors, we acknowledge that one of the authors PW is employed by Best Friends Animal Society, advocating for the protection of domestic cats via public policy initiatives. The remaining author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Alligator mississippiensis diet partitioning to demonstrate the power of this approach. Finally, we conclude with a discussion of limitations to mixing model applications. Through MixSIAR, we have consolidated the disparate array of mixing model tools into a single platform, diversified the set of available parameterizations, and provided developers a platform upon which to continue improving mixing model analyses in the future.The ongoing evolution of tracer mixing models has resulted in a confusing array of software tools that differ in terms of data inputs, model assumptions, and associated analytic products. Here we introduce MixSIAR, an inclusive, rich, and flexible Bayesian tracer  mixing model framework implemented as an open-source R package. Using MixSIAR as a foundation, we provide guidance for the implementation of mixing model analyses. We begin by outlining the practical differences between mixture data error structure formulations and relate these error structures to common mixing model study designs in ecology. Because Bayesian mixing models afford the option to specify informative priors on source proportion contributions, we outline methods for establishing prior distributions and discuss the influence of prior specification on model outputs. We also discuss the options available for source data inputs (raw data versus summary statistics) and provide guidance for combining sources. We then describe a key advantage of MixSIAR over previous mixing model software—the ability to include fixed and random effects as covariates explaining variability in mixture proportions and calculate relative support for multiple models via information criteria. We present a case study of  This basic formulation assumes that (1) all sources contributing to the mixture are known and quantified, (2) tracers are conserved through the mixing process, (3) source mixture and tracer values are fixed (known and invariant), (4) the kp terms sum to unity, and (5) source tracer values differ. Given a mixing system with multiple tracers such that the number of sources is less than or equal to the number of tracers + 1, the kp terms in the set of jY equations can be solved for analytically, given the unity constraint  to a consumer (mixture) diet, although other applications include animal movement, pollutant sourcing, cross-ecosystem nutrient transfer, and sediment erosion fingerprinting . In recenstraint . In mostnstraint . Additiokp terms that resulted in jY solutions falling near the true value of the mixture , where “near” was arbitrarily defined by the model user through the specification of tolerance. Subsequently, More recently, researchers have turned to more sophisticated mixing model formulations that provide probabilistic solutions to the mixing system that are not limited by the ratio of sources to tracers , and that integrate the observed variability in source and mixture tracer data. The first of such models, IsoSource , provideIn light of these analytic innovations, we have created an open-source R software package, MixSIAR, that unifies the existing set of mixing model parameterizations into a customizable tool that can meet the needs of most environmental scientists studying mixing systems. MixSIAR can be run as a graphical user interface or script, depending on the user’s familiarity with R. Either version can be used to load data files and specify model options; then MixSIAR writes a custom JAGS  diet partitioning. Finally, we discuss limitations of mixing models and issues with under-determined systems. The complete set of MixSIAR equations with additional explanation is included as https://github.com/brianstock/MixSIAR.In this paper we introduce and provide guidance on using MixSIAR for the application of Bayesian mixing models. Given early debate in the literature regarding appropriate error parameterizations , we begiIn most published results stemming from Bayesian mixing models, little if any detail is reported regarding the assumed error structure of the mixture data  combination of the source means. Observations of these means, however, are imperfect and thus the i mixture data for tracer j, ijY, are assumed to follow the distribution,j2 represents residual error variance, or the variability in observations associated with the mixture data points for the jth tracer. This error distribution is appropriate in situations where, for instance, each mixture data point was generated through the combination of many samples from the source population. For instance, if an analyst were interested in assessing the relative contributions of dissolved organic carbon and particulate organic matter to a filter feeder’s diet, this model formulation would be appropriate since each source tracer datum comes from an integrated sample of the source tracer values .Researchers sometimes use “integrated” or “composite” sampling—pooling many subsamples into one sample that is then analyzed—to characterize the source means while keeping processing time and costs low, or because individual consumers or prey do not have enough biomass to analyze . Thus, ti for tracer j is derived from a normal distribution with the same mean as in jks2:In contrast, for many mixing models applied to ecological systems, the tracers of individual source items  and mixtures  are analyzed separately, and the variability across source tracers is assumed to translate into consumer tracer variability—in other words, different wolves eat different deer, and their tracer values should differ accordingly . Since tIn situations where there is covariance in tracers , j tracers considered. This formulation must be used in this special case because it is not possible to estimate a variance term, σj2, from a single data point. In diet partitioning applications, the above formulation assumes that, for a given tracer j, a consumer i takes one independent and identically distributed (IID) sample from each of k sources and combines these samples in accordance with the proportional estimates kp. In other words, each wolf eats exactly one deer, and thus incorporates the tracer value of only that deer. Because the prey-specific tracer values will be different for each consumer due to sampling error, the weighted combination of sampled source tracer values will also vary. We refer to this model of mixture variance as “process error” because it is derived from an assumption about the mixing process.MixSIAR uses this model formulation only in the special case where the analyst provides a single mixture value for each of the j such thatRecently, j term is to both add biological realism in the mixing equation, and to provide flexibility on the likelihood error structure such that mixing data not conforming to the mixing process assumed in the previous likelihood formulation can still be fit appropriately. As before, kp point estimates and narrower 95% CI when the true mixture variance is low (ξj < 1).The intent of the ξj is less than 1, the variance in consumer tracer values shrinks, presumably due to the biological process of sampling each prey source multiple times from a distribution of tracer values , all mixtures do not have the same source proportions, or that the model is missing at least one source pool.Estimates of ξ routing , or impo routing . Alternap is the Dirichlet distribution; MixSIAR uses this distribution for estimates of source proportions. The Dirichlet is often referred to as a multivariate extension of the Beta distribution, and it is important to understand the Beta before transitioning to the Dirichlet. The Beta distribution has a convenient property that when both its shape parameters are 1, it is equivalent to a uniform distribution. In other words, if a model tries to estimate the relative contribution of a 2-component mixture, p1 ∼β  is equivalent to p1 ∼Uniform . Because the vector of proportions is constrained so that p2 can be treated as the derived parameter p2 = 1−p1, and therefore does not require a prior. For the parameter of interest p1, one way to describe the prior distribution is that the β  prior is uniform, and an equivalent description is that all possible combinations of p1 and p2 are equally likely a priori.The analysis of compositional data is not unique to mixing models. Examples of statistical models for compositional data are widespread in ecology , fisherip. The hyperparameter of the Dirichlet distribution is a vector α, whose length is the same as p. Like the Beta distribution, the only constraint on the elements of α is that they be positive . A common choice of hyperparameters for a 3-component mixture is α = , which we refer to as the “uninformative”/generalist prior because (1) while every possible set of proportions has equal probability, the marginal prior likelihood of a given kp differs across values of kp, and (2) its mean is p  implies that all combinations of  are equally likely. Thus, this prior is noninformative on the simplex, but is non-uniform with respect to individual kp parameters. Other choices of a prior may be Jeffreys’ prior, αk are set to 1.For mixtures with more than 2 components, MixSIAR uses the Dirichlet distribution to specify a prior on ist diet . The fir diet , where each αk corresponds to the source k sample size from the stomach contents. A downside of this prior is that a sample size of 63 represents a very informative prior, with much of the parameter space given very little weight . In such cases, we would want to downweight the prior’s significance, since a prior constructed from daily information should only be loosely informative on the mixture proportions averaged over weeks to months. Exactly how much to downweight is unclear. However, this challenge lies within the broader issue of how to weight multiple data types, and we follow In addition to specifying prior distributions on proportional contributions, MixSIAR requires priors on variance parameters . BecauseIn some cases, an analyst may wish to incorporate discrete or continuous covariates to explain differences between individual tracer values , their pEarly versions of Bayesian mixing models treated the estimates of source-specific tracer means and variance as fixed (user specified), and thus only used raw mixture data in calculating the likelihood of source proportions . In so dMixSIAR provides the analyst with each of these three options for including source data, because each can be appropriate in different circumstances . In orde13C, δ15N), it is unlikely the model products will be precise or interpretable. The source data  have a large influence on the estimated proportions. As such, including several largely extraneous sources with few mixture data points will divert kp from the truly important sources . This under-determination, together with the variability in source and mixture isotopic values, often results in quite diffuse probability distributions for many of the proportional contribution estimates, limiting the interpretability of the results (a priori or a posteriori aggregation (a posteriori aggregation).No amount of increased sophistication in mixing model methods can overcome the problem of poorly specified mixing systems. If, for instance, an analyst specifies a mixing model with >7 sources contributing to a mixture based on two tracers  to decide on whether sources should be combined a priori often presents problems. The amount of data available for each source directly influences the equality of the means tests; the power to reject a null hypothesis of no mean difference between tracer values of sources is thus related to the amount of tracer data, and is not exclusively a function of the mixing system. Furthermore, in situations when many tracers are available  also combines the prior weight for these sources. For instance, given an “uninformative”/generalist Dirichlet prior, the act of aggregating two source posteriors results in a combined source posterior that reflect an aggregated prior with twice the weight of the remaining non-aggregated source priors. As such, the more sources that are combined into an aggregate source group a posteriori, the more strongly the prior will be weighted towards increased proportional contributions of this aggregate source to the consumer diet. MixSIAR alerts users to this issue by plotting the aggregated prior when combining sources using the “combine_sources” function  are of different sexes and an analyst has interest in whether the dietary proportions differ between sexes .An analyst has additional numerical measures on the consumers such as weight, length, etc., and would like to see whether the dietary proportions are affected by this value (fixed continuous effect).An analyst has samples of consumers or sources in different regions. It is likely that the consumers’ dietary proportions are similar between regions so it makes sense that the estimates should ‘borrow strength’ between the groups (random effect).In many cases, covariate data  are available for incorporation into a Bayesian mixing model to answer important questions about the mixture . NeglectAlligator mississippiensis diet partitioning, which executes multiple model formulations and evaluates their relative support using information criteria . Third, there is no way to “borrow strength” between groups, since each set of dietary proportions must be estimated independently. The solution lies in adding the extra information as covariates through the dietary proportions in the mixing model directly. To illustrate the application of fixed and random effects using MixSIAR software we describe a case study on criteria .A common question is how to choose whether to use fixed or random effects. We recognize that the terms “fixed” and “random” effects are unclear , and in ikp is now the dietary proportion for source k on individual i.For covariates to be included, the model must allow for dietary proportions to be specified per individual, e.g., the mixture likelihood must be of a form similar to:p using a Dirichlet prior that can be modified with prior information. Once specified, these proportions are isometric log-ratio (ILR) transformed into ILR-space parameters, β0 .The parameters in the vector If the covariate is continuous, as in example 2, the structure changes only very slightly:β1 represent the change in dietary proportions according to a unit increase in the weight of the consumer.Now the parameters in the vector k−1 random effect terms in the vector i)Region, interpretation of model findings after back-transforming is prudent. MixSIAR therefore provides summary output statistics and preserves posterior draws on the back-transformed proportions for fixed categorical and random effects. In the case of continuous fixed effects (see below), MixSIAR generates a plot of the fitted line in the untransformed proportion space that spans the range of the provided covariate data. For the full set of MixSIAR equations and additional explanation, see Since there is no one-to-one relation between the original parts and the transformed variables , and how this varied with ontogeny , sex, and between individuals. They used 2-source , 2-tracer  mixing models and posed three questions:marinep vs. freshwaterp?Q1. What is marinep vary with the covariates Length, Sex, and Individual?Q2. How does Q3. How variable are individuals’ diets relative to group-level variability?This case study highlights the main advantage of MixSIAR over previous mixing model software—the ability to include fixed and random effects as covariates explaining variability in mixture proportions and calculate relative support for multiple models via information criteria. marinep estimates for the overall population, they also ran a mixing model with all consumers. In addition to inadequately addressing Q3 on individual diet variability, this approach is likely inefficient, as it fits nine residual error terms for each tracer and does not capitalize on the fact that diets of different-sex and different-sized alligators are probably related. We propose that a more natural, statistically efficient approach is to fit several models with fixed and random effects as covariates, and then evaluate the relative support for each model using information criteria (see “compare_models” function in MixSIAR).13C and δ15N values for each of 181 alligators), we can compare the models using information criteria. Deviance information criterion (DIC) is a commonly-used generalization of Akaike information criterion (AIC) for Bayesian model selection which estimates out-of-sample predictive accuracy using within-sample fits. DIC, however, has several undesirable qualities , while the “Length” model estimate of pmarine for the largest individual, a 315.5 cm adult male, is 0.96 . Although We found that the models with Length as a continuous fixed effect are heavily preferred over the models that break length into four size classes  is about what we expect given the assumptions about how predators sample prey. The ξC estimate (5.2) is very high, however, indicating that there remains an important process that is unaccounted for in the model. There are several possible explanations (see section on “Understanding MixSIAR error structures for mixture data”), with one being that individuals’ diets likely differ based on other processes than sex or length—all models in ith individual becomes:This case study also highlights the interaction between covariates and the multiplicative error term, ξpmarine for individual alligators to vary around the expectation based on Length . Some misspecifications are simple to fix, while other times they require a detailed examination of the likelihood or posterior distributions (which may appear flat with respect to the parameter of interest). Similar situations arise in all statistical models—for example fitting a regression model to a constant response Y =  returns an estimate that is a perfect fit to the data, but does not produce standard errors or test-statistics . Several recent papers have illustrated some of these same points with respect to mixing models, and we detail those here.Like any statistical model, inference from mixing models is only as good as the data being used. In some situations, data may not be informative—these situations may arise when models are misspecified or data are limited . Such situations may be difficult to diagnose, and we encourage mixing model users to reach out to other users and contributors (a priori). At present, MixSIAR does not provide the option to estimate discrimination from user-provided data, although such functionality could easily be added; we anticipate adding this functionality into a future software release.As a first limitation, A second limitation of mixing models is that systems may be underdetermined (as discussed in Introduction). a priori when these situations may arise. As such, we have incorporated Brett’s surface area metric as a diagnostic output in MixSIAR . However, work still needs to be done to generalize this metric to situations with any number of tracers and sources.The influence of the Dirichlet prior on the source proportions is a separate, but related, issue—the prior becomes more influential with more sources. Contrary to how this discussion has been framed previously , 2015, tAnalysts applying modern mixing model software typically must navigate a challenging array of model choices, from source groupings to covariate data, to error parameterization. In the past, those analysts not capable of developing their own models have been faced with the choice between different software packages, each with differing statistical model structures and assumptions. Through the creation of MixSIAR, we have incorporated the disparate suite of mixing model advances into a single tool with the flexibility to meet most analysts’ needs. Because MixSIAR is open source and collaborative, we anticipate that new developments in mixing model methods, from parameterizations to model performance diagnostics, will continue to be incorporated into the functionality of MixSIAR. As such, the software provides a single tool that can meet the diverse needs of the rapidly increasing pool of stable isotope analysts, and affords developers a platform upon which to continue improving and diversifying mixing model analyses.10.7717/peerj.5096/supp-1Supplemental Information 1Click here for additional data file.10.7717/peerj.5096/supp-2Supplemental Information 2Click here for additional data file.10.7717/peerj.5096/supp-3Supplemental Information 3Click here for additional data file.


The Haitian orphanage sector receives more than 70 million United States Dollars (USD) in foreign aid annually and continues grow; there are over 500 orphanages in Port-Au-Prince alone. An estimated 80% of the 30,000 children living in Haitian orphanages have at least one living parent.This research seeks to identify factors contributing to maternal-child separation in Port-Au-Prince to understand motivations and attitudes surrounding maternal-child separation. We hypothesized that poverty, health status, and current state of the family unit are influential in the mother’s decision to separate from her child.From June to August 2017, a chain referral sampling study was conducted in Port-Au-Prince and the surrounding metropolitan area. Seventy interviews were conducted with (1) Mothers – separated (n = 8) and non-separated (n = 48) – and (2) Community leaders exposed to maternal-child separation (n = 18). The semi-structured interview consisted of questions about (1) exposure to maternal-child separation, (2) circumstances surrounding maternal-child separation, and (3) factors contributing to maternal-child separation. Additionally, all mothers completed a survey including demographic information and multiple validated surveys: Maternal Postpartum Quality of Life, Patient Health Questionnaire (PHQ-9), and PTSD Checklist (PCL) to address quality of life, depression, and PTSD, respectively.This study found separation to be associated with poor economic means compounded with other factors, most notably access to education, ability to care for disabled children, insufficient support, and poor maternal mental health. Additional themes identified include negative stigma towards maternal-child separation and sparse education surrounding family planning. Quantitative findings revealed separated mothers experienced significantly higher rates of PTSD compared to non-separated, small but statistically worse quality of life, and no difference in rates of major depression.This research finds economic means to be insufficient in predicting maternal-child separation, with access to education being the most salient contributing factor mentioned after economics. Findings from this study will inform development of programming focusing on education, family planning, and social support in Port-Au-Prince. An estimated 30,000 children live across 750 orphanages in Haiti, with over 500 orphanages in Port-Au-Prince alone. The Haitian government estimates 80% of these children have at least one living parent and nearly all have other family members. Despite this, the orphanage sector continues to thrive .Developed countries that fund the orphanage sector, including Australia, European countries, and the United States, have themselves departed from orphanage-based care in favor of family-based foster systems . In 19892The outcomes of orphanage care are well established, but the Haitian orphanage sector continues to grow; contradicting international trends, UN child protection conventions and standards, and the Haitian Government’s national plan to reduce reliance on orphanage care and decrease human trafficking. Economic and political instability, poverty, foreign intervention, and natural disasters have influenced the current environment where it is not uncommon for Haitian women to struggle to provide for their children . Followi1The size and wealth of the orphanage sector overpowers L’Institut du Bien-Etre Social et de Recherches (IBESR) – the Haitian government agency responsible for child welfare – as the agency’s annual budget is less than 750,000 USD. In 2015, IBESR adopted a 2016–18 strategy to reduce reliance on orphanage care and enforce regulations on orphanages. IBESR has been able to officially register 15% of orphanages and close several unsafe orphanages, but its capacity to monitor orphanages and enforce regulations is limited . I didn’t have a chance to go to school, so I didn’t want my children to turn out like me, to not be able to go to school. So I thought it would be good for them to be [in the orphanage].”“Compulsory free primary education would help solve a lot of problems, with the mandate that it be inclusive and that children with disabilities had equal access to it.”The MAPP-QOL partner/spouse subsection asks mothers to describe their satisfaction with their partner/spousal support and home environment. Greater scoring indicates a greater feeling of satisfaction. The partner scores were found to be significantly different between separated and non-separated mothers with a p-value of <0.01. Figure . The bur“The other cases that present very often are of fathers who do not take up their responsibility. The fathers say they are not willing to take care of the child. If the father leaves, the woman at a certain point may know she cannot take care of the child.”“The biggest factor is abandonment of the father in the first place.”“They lived in a very disadvantaged area and is located in the south side of Port-Au-Prince known as a no man’s land. In that area there are particular issues of insecurity, particularly money, shelter, and food. So in that case the women had no means necessary and did not even know who the father was.”When prompted to consider social and family support in the role of maternal-child separation, mothers and community leaders overwhelmingly agree that these forms of support are crucial in a mother’s decision. The interview question was intentionally open-ended such that participants could address any form of support. Several participants suggested lack of support in the form of social services is contributory to maternal-child separation.“I didn’t have anyone to help me, to support me, so I had to put my kid in the orphanage.”“Most of the time, the person doesn’t have any support from her family or from the society, so that’s usually why she decides to abandon her child.”“There is no society to help a mother in need and if she had social support she wouldn’t have come to this decision [to abandon].”“When my husband was still alive… he could look after the children. Since he is not around anymore and I need to go out every day to work, I cannot look after them. If they keep going outside to the neighbors, they keep playing, everyday people come to tell her things they have done. Sometimes even if they didn’t do something, [the neighbors] accuse them… So I decided not to keep them anymore, to put them in an orphanage, because I cannot spend my days looking after them.”Despite the relative frequency of maternal-child separation in Port-Au-Prince, maternal-child separation retains a negative association as seen in other parts of the world. A negative stigma towards the concept of maternal-child separation manifests in variable ways. Few mothers and community leaders openly express disdain for mothers who separate from a child. Many distanced themselves from maternal-child separation by understating their knowledge of or relationship to separated families. Several participants described varying definitions of the word “abandone” allowing for non-traditional living arrangements to be considered more socially acceptable while elucidating how a wide range of living situations may or may not be considered separation based on the intention of the mother.“Once you give birth to a kid, you should find any way to take care of him, find any job to take care of him. Lack of [social and family] support shouldn’t be a reason why [a mother abandons], because you are responsible for that kid.”“I haven’t met any mothers who have abandoned their kids… [My neighbor] called me downstairs and told me she was having a baby and needed help… I decided if [the baby is] alive, [my neighbor] can’t just kill it… I tried to find a place to take the baby, but the orphanage said the baby is too young so I kept him for a while.”“In Haiti, culturally children are a benediction, a blessing, and in a lot of disadvantaged communities, children are a blessing and the child is hope to bring them out of where they are… In good Kreyol, it means picking that family up from the ground. According to the community, their perception of a person abandoning the child is very negative.”In Haiti, a frequently discussed and accessible form of contraception is a contraceptive injection , referred to as “planning.” These findings suggest great concern regarding a wide range of potential and perceived adverse events from the contraceptive injection. In the event that mothers are unable to use the injection, many resort to having unprotected sex due to the perception that there are no other available methods or that intermittent use may be sufficient to prevent pregnancy. In addition to the sparse use of contraception, many mothers report unplanned pregnancies or state that the number of “planned” pregnancies exceeds the number of children they had hoped to have. The latter is more frequently the case with married mothers who describe the marriage itself as a plan to have children.“I used to use planning but I am allergic to it… I used an injection called Confiance…. I didn’t plan to have children, so they were all accidents. I was pregnant 8 times. I had 2 abortions and lost 1 and gave birth to 5.”“I know where to get it. It’s accessible and I have the resources, but I am not on a contraceptive. Because I don’t want to gain weight, because the injections that they give [at the clinic] make me gain weight.”“I think that women who need to have family planning or contraception are women who are married or live with a partner. Since I don’t live with my partner, I don’t use any contraceptives. Once in a while, I think about it. When I have time, we have sex, so I don’t need any contraception… Since I already have a kid, I love him, so I will stay with him… but the next baby I will have, I will make sure to get married and follow everything the bible says before having another baby.”“[Pregnancy is] only not accident when you married. When you married it’s welcoming but when you not married it’s a whole different thing.”Child disability was not found to be a factor in maternal-child separation. However, it was described as financially burdensome, a cause for community judgement, and a contributing factor in paternal absence. These associations, while not found to be a contributing influence in a mother’s decision to separate from a child, demonstrate the complexity of being a parent with a disabled child in Port-Au-Prince.“We are in a society where there is no real good access to public healthcare, there is no insurance really, and the financial costs with a child with a disability or chronic medical condition will drown a family financially indefinitely… ‘If I keep this child, I have to keep paying for speech, or wheelchairs, or rehab, or whatever that is and I can no longer pay for school for my other children,’ and sometimes it’s a matter of trying to make the best out of a terrible situation.”“In case of the child being born handicapped, the mother receives pressure from the father saying, “No this is not my child. This is your child.” Because the child is handicapped. Eventually humiliation from other people in the community will have that woman abandon that child even if she wanted to keep that child.”Women participating in the survey described fear that community members would perceive their struggle, and that this fear affects their decisions. No participants openly expressed judgement towards struggling community members, though several mothers distanced themselves from neighbors in efforts to conceal the magnitude of their own struggles. Many discussed the experience of or the fear of being judged.“I wake up every morning and go to my small business, because I need the money to handle my stuff, to take care of myself, and because I can’t go to church dressed any-how. I need to be dressed to impress so people don’t know how I am living.”“When life is easy for us, we are happy. When it’s not, we deal with it and we pray that it will get better… I used to go to church regularly, but since I started to have a lot of problems I stopped, because I cannot go to church dressed neglectfully.”“Everybody handles their own stuff. Nobody goes to the neighbors, and everybody stays at their place to handle their own things.”The PHQ-9 depression severity scoring validity has been assessed against an independent structured mental health professional (MHP) interview. PHQ-9 score ≥10 had a sensitivity of 88% and a specificity of 88% for major depression. Of all 49 mothers who completed the PHQ-9 survey, approximately 76% 37 mothers) received scores indicating mild to moderate depression. However, PHQ-9 scores were not found to be statistically different between separated and non-separated mothers  , and poor maternal mental health. Additional findings of this study include limited use of family planning, stigma towards maternal-child separation, and the economic and social burden of having a disabled child.Haitian culture upholds children as a blessing to all families and that circumstances surrounding maternal-child separation are complex and emotional. Mothers and community leaders alike expressed that the decision to separate is not made lightly and is a consequence of necessity.It should be noted that many participants in this study emphatically expressed that Our findings are consistent with previous research that highlights the multifactorial situation surrounding maternal-child separation in other low-income countries. A UNICEF study in Vietnam found that poverty was the self-reported primary reason for mothers initiating separation but was insufficient in predicting separation. Rather poverty was associated with separation only when compounded with other factors including lack of social support, lack of access to social assistance, paternal absence, or unwanted pregnancy. In such situations, “the idea or suggestions from others to place a child either in an institution or to relinquish him or her for adoption were perceived as a window of opportunity .”Limitations of this study include the small number of separated mothers. The relatively small number of separated mothers included in the study caused our analysis to weigh each of their responses more heavily, possibly biasing the results away from the null. When considering difficulties with recruiting separated mothers, it is worth noting that the small proportion of participants reporting separation contrasts with the large volume of children in Haiti’s orphanages that have at least one living parent. This dissonance raises questions about stigma and the reluctance to disclose separation. In order to greater power our findings, further studies with larger sample sizes are necessary.Despite limitations, this study provides evidence to support possible interventions to support families in the Port-Au-Prince area. The prenatal period is likely optimal for screening and connecting high-risk mothers to resources to reduce separation in the immediate sense. An additional potential point of intervention identified is education surrounding family planning to reduce unplanned pregnancies. A randomized controlled trial in Nepal found that a 20-minute health education session for mothers directly following childbirth lead to increased likelihood of contraceptive use six months postpartum . A standAnother point of intervention identified is improvement of maternal mental health, particularly PTSD and depression. Psychological and psychiatric intervention for mothers and families could improve maternal mental health at the individual level. In addition, community-level intervention should be considered to address social determinants of mental health. A World Health Organization meta-analysis identified social determinants of perinatal mental health including poor or overcrowded living conditions, community violence, and social instability . In low-Our findings point towards better access to schooling, for both children and mothers, as critical in prevention of maternal-child separation. Lack of access to education was cited as a major reason for maternal-child separation by majority of participants. Free or low-cost schools could address children’s access to education . These sLastly, efforts should be made to streamline and reallocate international aid that supports the orphanage system to resources that support family stability and reunification such as free education, school meals, and daycare facilities, which would ease the financial burden on parents while allowing them time to pursue employment. Efforts of many NGOs and the Haitian government have created a complex landscape of resources in Port-Au-Prince that must be adequately navigated to support mothers and children and mitigate risk of maternal-child separation.Future directions involve researching the generalizability of these findings to the population of Port-Au-Prince. To the extent that factors identified in this study are generalizable, the challenge will be finding ways of remedying vast and endemic issues such as poverty and access to schooling and studying their impact on maternal-child separation. Such studies would likely need to occur on a small scale, at the level of neighborhoods. This will likely introduce practical and ethical challenges. Regardless of future findings on the topic of maternal-child separation, remedying social ills like poverty or lack of education would constitute accomplishments in themselves with dividends extending incalculably far beyond maternal-child separation.