Most young adults gain weight while attending college, setting the stage for long-term weight gain, and associated chronic disease. Interventions that use social and mobile technologies, and leverage social network support may help students adopt health-enhancing habits such as regular exercise.

The first study explored how overweight/obese college students participating in project SMART (N = 404), a remotely delivered two-year weight loss trial, engaged their social networks, and used social and mobile technologies while trying to lose weight. The second study tested whether participants in the treatment (versus control) group talked more about diet and exercise with their FB friends, and the third study tested whether this type of online communication, and receiving social support for it was associated with weight loss.

Study one involved qualitative interviews with a convenience sample of participants (n=38), intercepted after one of their measurement visits. Study two involved building a dictionary of diet and exercise words that was used to classify participants’ FB posts as being about HAL or not. Study three quantified the number of likes and comments on posts (i.e., social support), and tested whether posting about HAL or receiving social support for HAL was associated with weight loss.

Study one found that participants in the control and treatment groups used non-study designed apps to help them lose weight and many participants knew one another. Individuals talked about their weight-loss goals with friends and felt accountable to follow through with their intentions. Study two found that treatment group participants posted more HAL than those in the control from baseline to +6 months of participation (Beta=1.75; p<0.05) but this effect did not persist over time. Study three found no association between HAL posts and weight loss but the association between social support for HAL posts and weight loss (kg) approached significance at +18 months of participation (Beta= -0.20; p=0.07).

Interventions using social and mobile technologies should measure participants’ direct-to-consumer technology use, and interconnectivity so that treatment effects can be isolated and cross-contamination accounted for. Future work will test how social network connections, and network structure is associated with weight loss among this population.

In vertebrates, hepcidin is the peptide hormone that homeostatically regulates the body's supply of elemental iron, an indispensible reactant in many biological processes. Worldwide over a billion people are affected by diseases associated with iron imbalance. These conditions can be categorized as disorders in which hepcidin responds physiologically and disorders in which hepcidin is dysregulated. In the former, lack of dietary iron appropriately suppresses hepcidin to maximize dietary iron absorption capacity. Iron-restricted anemia can develop, nevertheless, if the iron content of food is not sufficient. In the latter, inappropriate hepcidin stimulation by cytokines, during chronic inflammation for example, reduces plasma iron and anemia results despite adequate levels of dietary and body iron.

Iron absorption depends on the interaction between hepcidin and its receptor, the iron exporting channel, ferroportin. When hepcidin activity is insufficient, iron pathways saturate and excess iron intoxicates the organs in which it accumulates. When plasma iron levels need to be reduced, hepcidin is secreted by the liver into circulation where it finds ferroportin and initiates its internalization and degradation. Plasma iron flow is thus blocked from the principle ferroportin-expressing cell types including, but not limited to, enterocytes, macrophages of the spleen and liver and hepatocytes until an unknown signaling mechanism suppresses hepcidin production to allow iron to flow to sites of need.

How the liver moderates hepcidin production in response to increased body iron is still not completely understood, but Chapter 1 of this dissertation, describes the use of mouse models of hepcidin deficiency to define two signals that independently regulate hepcidin production. Chapter 2 builds on a collaboration described in Chapter 3, and details the optimization and use of hepcidin mimetics to treat iron overload caused by hepcidin deficiency. Chapter 4 is another collaboration that elucidates novel signaling pathways that suppress hepcidin and their connection to iron overload in conditions that damage cells of the liver.

In Vietnam and its diaspora, the đàn bầu monochord zither is a symbol of cultural pride. Based on fieldwork conducted in Vietnam and in diaspora communities between 2015-2017, this study of the đàn bầu argues that the instrument is a site where state institutions, individual musicians, and audiences in Vietnam and the diaspora articulate myriad narratives of personal and national identities. In contemporary Vietnam, the state maintains a discourse that positions the đàn bầu as a musical representative of national culture, rooted in an imagined past.

In the diaspora, the đàn bầu is similarly emblematic of Vietnamese identity, but the dimensions of the “nation” are continually in flux. Due to legacies of trauma in the diaspora, musicians and audiences actively separate Vietnamese culture from the current nation state. The đàn bầu represents Vietnamese heritage, while also articulating the personal and political concerns of life in the diaspora. Musicians use the đàn bầu to traverse political and aesethetic expectations in Vietnam, in diaspora communities, and in the liminal space of tourist performance.

This dissertation addresses the ways in which the Ainu tonkori, a fretless zither, has come to represent the resurgence of Ainu performing arts in Japan as an important identity marker for the Ainu as a minority culture that is commonly perceived to be extinct by most people in Japanese society. The dissertation traces Ainu historical engagement with the Japanese, starting with the Jomon Neolithic period through successive stages of trade, colonization, and assimilation. By tracing these periods of engagement, we can observe how cross-cultural influences have affected the tonkori and its tradition, and how subjugation practices from colonization led to the rise of Ainu social movements and the reconstruction of a new performing arts genre with the tonkori as its main instrument.

The dissertation presents Ainu performing arts as a contemporary phenomenon, one that is being newly created and currently in a transformative process, initiated by key musicians who are also cultural and political leaders. The tonkori is emblematic as a musical instrument that allows its practitioners to convey a distinct Ainu indigeneity within Japanese society, a notion that challenges accepted beliefs in Japan of a homogeneous ethnic identity. This work addresses the roles of individual musicians within the Ainu social movement as mediators engaging with Japanese and international institutions and also as bearers of a newly emerging musical tradition.