The Proper Motion Field Along the Magellanic Bridge: a New Probe of the LMC-SMC Interaction

We present the first detailed kinematic analysis of the proper motions (PMs) of stars in the Magellanic Bridge, from both the \textit{Gaia} Data Release 2 catalog and from \textit{Hubble Space Telescope} Advanced Camera for Surveys data. For the \textit{Gaia} data, we identify and select two populations of stars in the Bridge region, young main sequence (MS) and red giant stars. The spatial locations of the stars are compared against the known H {\small I} gas structure, finding a correlation between the MS stars and the H {\small I} gas. In the \textit{Hubble Space Telescope} fields our signal comes mainly from an older MS and turn-off population, and the proper motion baselines range between $\sim 4$ and 13 years. The PMs of these different populations are found to be consistent with each other, as well as across the two telescopes. When the absolute motion of the Small Magellanic Cloud is subtracted out, the residual Bridge motions display a general pattern of pointing away from the Small Magellanic Cloud towards the Large Magellanic Cloud. We compare in detail the kinematics of the stellar samples against numerical simulations of the interactions between the Small and Large Magellanic Clouds, and find general agreement between the kinematics of the observed populations and a simulation in which the Clouds have undergone a recent direct collision.Comment: 13 pages, 10 figures, 2 tables, submitted to ApJ, accepted February 8th, 201

Compartmentation of Redox Metabolism in Malaria Parasites

Malaria, caused by the apicomplexan parasite Plasmodium, still represents a major threat to human health and welfare and leads to about one million human deaths annually. Plasmodium is a rapidly multiplying unicellular organism undergoing a complex developmental cycle in man and mosquito – a life style that requires rapid adaptation to various environments. In order to deal with high fluxes of reactive oxygen species and maintain redox regulatory processes and pathogenicity, Plasmodium depends upon an adequate redox balance. By systematically studying the subcellular localization of the major antioxidant and redox regulatory proteins, we obtained the first complete map of redox compartmentation in Plasmodium falciparum. We demonstrate the targeting of two plasmodial peroxiredoxins and a putative glyoxalase system to the apicoplast, a non-photosynthetic plastid. We furthermore obtained a complete picture of the compartmentation of thioredoxin- and glutaredoxin-like proteins. Notably, for the two major antioxidant redox-enzymes – glutathione reductase and thioredoxin reductase – Plasmodium makes use of alternative-translation-initiation (ATI) to achieve differential targeting. Dual localization of proteins effected by ATI is likely to occur also in other Apicomplexa and might open new avenues for therapeutic intervention

A Different Shade of Grey: Intimacies of Older Filipino Gay Men in Canada

This dissertation is a qualitative study, which examined the experiences of intimacy of the older Filipino gay men in Canada. These group of men identify as bakla, which is the Filipino term for queer or non-normative gender and sexual identity, practices, and performances. I specifically investigated how older bakla engage and express their intimacies with the three significant groups of people in their lives, namely, their sexual partner, their family or bloodrelated kin, and their friends. The purpose of such inquiry was to understand the relationship dynamics that older bakla have with these three groups. Such significant figures are the potential sources of social and emotional support of the older bakla. Intersectionality theory from a queer diasporic–feminist gerontological lens informed the study that takes into account the social location of the informants in terms of sexuality and gender, race, diaspora, age, and class. In this study, I used both participant observations and in-depth interviews as the main methods of data collection. These methods were informed by a culturally-grounded approach, called kuwento, a Filipino version of storytelling. This type of storytelling allowed the informants of the study to articulate their experiences in a manner that was comfortable, accessible, and convenient for them. Using grounded theory for data analysis, older bakla revealed a different experience of iii intimacy with their significant others. A story of difference exists, because they do not necessarily resonate to the dominant stories of aging. Their stories of intimacies offer critique of the norms and dominant discourses of identity. As well, older bakla’s intimacies illuminate their sense of agency in negotiating the norms of gender, sexuality, ageing, class, diaspora, and race that have marginalized and oppressed their beings and subjectivities. In the conclusion, I discuss how their intimacies with significant others, which are conditioned by uncertainty, impact their well-being and ageing bodies and how these informed critical social work education and practice. This study offers important contributions to the field of gerontological social work, sexuality and queer studies, migration and transnationalism, and anti-oppressive epistemologies.Ph.D.2021-07-21 00:00:0

The Missing Satellites of the Magellanic Clouds? Gaia Proper Motions of the Recently Discovered Ultra-faint Galaxies

According to LCDM theory, hierarchical evolution occurs on all mass scales, implying that satellites of the Milky Way should also have companions. The recent discovery of ultra-faint dwarf galaxy candidates in close proximity to the Magellanic Clouds provides an opportunity to test this theory. We present proper motion (PM) measurements for 13 of the 32 new dwarf galaxy candidates using Gaia data release 2. All 13 also have radial velocity measurements. We compare the measured 3D velocities of these dwarfs to those expected at the corresponding distance and location for the debris of a Large Magellanic Cloud (LMC) analog in a cosmological numerical simulation. We conclude that four of these galaxies (Hor1, Car2, Car3, and Hyi1) have come in with the Magellanic Clouds, constituting the first confirmation of the type of satellite infall predicted by LCDM. Ret2, Tuc2, and Gru1 have velocity components that are not consistent within 3 sigma of our predictions and are therefore less favorable. Hya2 and Dra2 could be associated with the LMC and merit further attention. We rule out Tuc3, Cra2, Tri2, and Aqu2 as potential members. Of the dwarfs without measured PMs, five of them are deemed unlikely on the basis of their positions and distances alone being too far from the orbital plane expected for LMC debris (Eri2, Ind2, Cet2, Cet3, and Vir1). For the remaining sample, we use the simulation to predict PMs and radial velocities, finding that Phx2 has an overdensity of stars in DR2 consistent with this PM prediction.NSF CAREER award [1455260]; Hellman Foundation; DPACThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Migration and health study: a socio-ecological analysis of sexual health among migrants in Manitoba, Canada

Abstract Background To develop effective public health policies, programs, and services tailored to the unique sexual health needs of migrant populations, it is essential to understand the myriad socio-ecological factors that influence their sexual health. This qualitative community-based participatory study aimed to explore factors influencing migrants’ sexual health at different socio-ecological levels in a Canadian setting. Methods Participants (n = 34) from African, Caribbean, Black; Latin American; South Asian; Middle Eastern, as well as East and Southeast Asian communities were recruited across Manitoba using printed flyers, community organizations, and social media. Individual interviews, conducted in English, French, Mandarin, Cantonese, Tagalog, Arabic, Swahili, and Tigrinya languages, explored questions relating to sexual health and experiences with service providers. Data were analyzed using reflexive thematic analysis and socio-ecological systems theory. Results The study uncovered a range of individual, interpersonal, institutional, and socio-structural factors that affect the sexual health of migrants in Manitoba. Individual factors such as sexual health knowledge and testing practices, interpersonal factors like the type of sexual partnerships, institutional factors such as sexual health information needs, language, and service access barriers, and structural-level factors like gender norms and HIV stigma exerted a significant influence on the sexual health practices of study respondents. Sexual health awareness was influenced by various factors including length of time in Canada and involvement in community-based services. Study respondents identified issues related to access to HIV testing and sexual health information, as well as language barriers, racism in healthcare, and HIV stigma. Gender and social norms played a significant role in discouraging communication about sex and safer sex practices. Conclusions The study highlights the complex interplay of factors that influence the sexual health of migrants, and the need for targeted sexual health awareness campaigns and provision of sexual health information in languages spoken by migrants. Public health interventions focused on improving the sexual health outcomes for migrants should consider the socio-ecological elements identified in this study. These findings can inform public health campaigns to increase access to services and address sexual health inequities among migrant communities in Canada