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Open Access Publications from the University of California

Scholarly Works (87 results)

  • Article
  • Peer Reviewed
Clinical Practice and Cases in Emergency Medicine, Volume 2, Issue 3 (2018)
    Cover page: CPC-EM Full Text Issue
    • Article
    • Peer Reviewed
    Clinical Practice and Cases in Emergency Medicine, Volume 3, Issue 1 (2019)
      Cover page: CPC-EM Full-Text Issue
      • Article
      • Peer Reviewed
      UC Santa Barbara Previously Published Works (2016)
      The cosmic microwave background (CMB) is one of the finest probes of cosmology. Its all-sky temperature and linear polarization fluctuations have been measured precisely at a level of δT/TCMB∼10-6. In contrast, circular polarization (CP) of the CMB has not been precisely explored. The current upper limit on the CP of the CMB is at a level of δV/TCMB∼10-4 and is limited on large scales. Some of the cosmologically important sources which can induce a CP in the CMB include early Universe symmetry breaking, a primordial magnetic field, galaxy clusters, and Pop III stars (also known as the first stars). Among these sources, Pop III stars are expected to induce the strongest signal with levels strongly dependent on the frequency of observation and on the number, Np, of the Pop III stars per halo. Optimistically, a CP signal in the CMB resulting from the Pop III stars could be at a level of δV/TCMB∼2×10-7 in scales of 1° at 10 GHz, which is much smaller than the currently existing upper limits on the CP measurements. Primary foregrounds in the cosmological CP detection will come from the galactic synchrotron emission, which is naturally (intrinsically) circularly polarized. We use data-driven models of the galactic magnetic field, thermal electron density, and relativistic electron density to simulate all-sky maps of the galactic CP. This work also points out that the galactic CP levels are important below 50 GHz and is an important factor for telescopes aiming to detect primordial B modes using CP as a systematic rejection channel. In this paper, we focus on a SNR evaluation for the detectability of the Pop III induced CP signal in the CMB. We find that a SNR higher than unity is achievable, for example, with a 10 m telescope and an observation time of 20 months at 10 GHz, if Np≥100. We also find that, if frequency of observation and resolution of the beam is appropriately chosen, a SNR higher than unity is possible with Np≥10 and resolution per pixel ∼1 μK at an observation time of 60 months.
        Cover page: Circular polarization of the CMB: Foregrounds and detection prospects
        • Article
        • Peer Reviewed
        UC San Francisco Previously Published Works (2016)
          • Article
          • Peer Reviewed
          UCLA Previously Published Works (2021)
          Diabetes disproportionably affects minorities in the United States. Substantial disparities exist in diabetes incidence, glycemic control, complications, mortality, and management. The most important biologic contributors to diabetes disparities are obesity, insulin resistance, and inadequate glycemic control. Providers and health systems must also recognize the behavioral, social, and environmental factors that promote and sustain racial/ethnic differences in diabetes and its complications. Metformin and sodium-glucose cotransporter 2 inhibitors are the most convenient drugs for treatment of diabetes in minority patients. Multilevel interventions at the patient, provider, health system, community, and policy levels are needed to reduce diabetes disparities in high-risk groups.
            Cover page: Ethnic Disparities in Diabetes
            • Thesis
            • Peer Reviewed
            UC Santa Cruz Electronic Theses and Dissertations (2013)

            ABSTRACT

            Indigenous Genocidal Tracings: Slavery, Transracial Adoption, and the Indian Child Welfare Act

            by Soma de Bourbon

            Indigenous Genocidal Tracings: Slavery, Transracial Adoption, and the Indian Child Welfare Act is a feminist, interdisciplinary history that traces the genealogy of U.S. property interests in Indigenous people from enslavement to the continued transracial adoption of Native children. The interconnection of Native history with that of Black Americans is interrogated, paying critical attention to the ways in which both communities continue to suffer overrepresentation in prisons, jails, juvenile detention centers, reproductive control programs, and child welfare systems (foster and adoptive care).

            In contrast to the work on Native transracial adoption (TRA) that has focused almost exclusively on outcome, the dissertation argues that Native TRA constitutes a group-based harm and situates it within the active process of settler colonialism and genocide. Specific attention is paid to slavery, land dispossession, boarding schools, adoption programs (such as the Indian Adoption Project and the Mormon Placement Program), and the creation of "unfit" women and "unwanted" children. Drawing on the Association on American Indian Affairs archives, the dissertation argues that the ways in which putatively "unfit" Native women fought back were the impetus for one of the most important federal Indian laws ever passed by Congress, The Indian Child Welfare Act (ICWA).

            The dissertation's chapters investigate the history of ICWA and the ways that state courts continue to violate ICWA's intentions by circumventing it through judicially created exceptions such as the Existing Indian Family. Through personal interviews with members of the Christian Alliance for Indian Child Welfare (CAICW), an organization that works to defeat ICWA, the author highlights the way CAICW's work can be seen as an example of the current landscape of ownership over Native people. Indigenous Genocidal Tracings ends with the work of the First Nations Repatriation Institute and its Director and co-founder Sandy White Hawk to illustrate not only the amazing survivance of Native people, but also the fact that Native people continue to find Native-centered ways of ameliorating the harmful effects of transracial adoption and colonization.

              Cover page: Indigenous Genocidal Tracings: Slavery, Transracial Adoption, and the Indian Child Welfare Act
              • Article
              • Peer Reviewed
              UC San Diego Previously Published Works (2021)

              Background

              Polycomb proteins are essential for maintaining stem cell identity across different stem cell niches. However, how they function to maintain stem cell niches is not fully understood.

              Results

              Here we show that the SERTAD protein Taranis (Tara), which is a Polycomb-trithorax group protein, is expressed in the adult testis niche and plays a role in its maintenance in Drosophila. We found that tara is expressed in early cyst cells, likely including somatic cyst stem cells (CySCs) of Drosophila male testis tip region, which houses both germline and somatic cyst stem cells along with the hub cells, forming the stem cell niche. Consistent with its expression, we found that, while loss of tara in germline cells only had minimal effects, tara knockdown in all cells or only in somatic cells of the niche reduced the number of not only somatic cells, but also germline stem cells (GSCs). We further found that Tara might antagonize Notch signaling in CySCs to maintain the stem cell niche.

              Conclusions

              Our studies suggest that Tara might function in somatic CySCs for GSC maintenance in the Drosophila testis.
                • Article
                • Peer Reviewed
                UC Davis Previously Published Works (2015)
                Across invertebrates and vertebrates, steroids are potent signaling molecules that affect nearly every cell in the organism, including cells of the nervous system. Historically, researchers have focused on the genomic (or "nuclear-initiated") effects of steroids. However, all classes of steroids also have rapid non-genomic (or "membrane-initiated") effects, although there is far less basic knowledge of these non-genomic effects. In particular, steroids synthesized in the brain ("neurosteroids") have genomic and non-genomic effects on behavior. Here, we review evidence that estradiol has rapid effects on aggression, an important social behavior, and on intracellular signaling cascades in relevant regions of the brain. In particular, we focus on studies of song sparrows (Melospiza melodia) and Peromyscus mice, in which estradiol has rapid behavioral effects under short photoperiods only. Furthermore, in captive Peromyscus, estrogenic compounds (THF-diols) in corncob bedding profoundly alter the rapid effects of estradiol. Environmental factors in the laboratory, such as photoperiod, diet, and bedding, are critical variables to consider in experimental design. These studies are consistent with the hypothesis that locally-produced steroids are more likely than systemic steroids to act via non-genomic mechanisms. Furthermore, these studies illustrate the dynamic balance between genomic and non-genomic signaling for estradiol, which is likely to be relevant for other steroids, behaviors, and species.
                  Cover page: Rapid Effects of Estradiol on Aggression in Birds and Mice: The Fast and the Furious
                  • Article
                  • Peer Reviewed
                  UCLA Previously Published Works (2019)
                  In females, a hallmark of puberty is the luteinizing hormone (LH) surge that triggers ovulation. Puberty initiates estrogen positive feedback onto hypothalamic circuits, which underlie the stimulation of gonadotropin releasing hormone (GnRH) neurons. In reproductively mature female rodents, both estradiol (E2) and progesterone (P4) signaling are necessary to stimulate the surge release of GnRH and LH. Estradiol membrane-initiated signaling facilitates progesterone (neuroP) synthesis in hypothalamic astrocytes, which act on E2-induced progesterone receptors (PGR) to stimulate kisspeptin release, thereby activating GnRH release. How the brain changes during puberty to allow estrogen positive feedback remains unknown. In the current study, we hypothesized that a critical step in estrogen positive feedback was the ability for estradiol-induced neuroP synthesis. To test this idea, hypothalamic neuroP levels were measured in groups of prepubertal, pubertal and young adult female Long Evans rats. Steroids were measured with liquid chromatography tandem mass spectrometry (LC-MS/MS). Hypothalamic neuroP increases from pre-puberty to young adulthood in both gonad-intact females and ovariectomized rats treated with E2. The pubertal development of hypothalamic E2-facilitated progesterone synthesis appears to be one of the neural switches facilitating reproductive maturation.
                    • Article
                    • Peer Reviewed
                    UCLA Previously Published Works (2021)
                    BACKGROUND: Cardiovascular disease (CVD) is a major cause of morbidity and mortality among people living with HIV (PLWH), but statin therapy, safe and effective for PLWH, is under-prescribed. This study examined clinic leadership and provider perceptions of factors associated with statin prescribing for PLWH receiving care in eight community health clinics across Los Angeles, California. METHODS: We conducted semi-structured telephone interviews with clinic leadership and providers across community health clinics participating in a larger study (INSPIRE) aimed at improving statin prescribing through education and feedback. Clinics included federally qualified health centers (N = 5), community clinics (N = 1) and county-run ambulatory care clinics (N = 2). Leadership and providers enrolled in INSPIRE (N = 39) were invited to participate in an interview. We used the Consolidated Framework for Implementation Research (CFIR) to structure our interview guide and analysis. We used standard qualitative content analysis methods to identify themes within CFIR categories; we also assessed current CVD risk assessment and statin-prescribing practices. RESULTS: Participants were clinic leaders (n = 6), primary care physicians with and without an HIV specialization (N = 6, N = 6, respectively), infectious diseases specialists (N = 12), nurse practitioners, physician assistants and registered nurses (N = 7). Ninety-five percent of providers from INSPIRE participated in an interview. We found that CVD risk assessment for PLWH is standard practice but that there is variation in risk assessment practices and that providers are unsure whether or how to adjust the risk threshold to account for HIV. Time, clinic and patient priorities impede ability to conduct CVD risk assessment with PLWH. CONCLUSIONS: Providers desire more data and standard practice guidance on prescribing statins for PLWH, including estimates of the effect of HIV on CVD, how to adjust the CVD risk threshold to account for HIV, which statins are best for people on antiretroviral therapy and on shared decision-making around prescribing statins to PLWH. While CVD risk assessment and statin prescribing fits within the mission and workflow of primary care, clinics may need to emphasize CVD risk assessment and statins as priorities in order to improve uptake.
                      Cover page: Factors affecting statin uptake among people living with HIV: primary care provider perspectives.
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