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Open Access Publications from the University of California

Scholarly Works (23 results)

  • Article
  • Peer Reviewed
Queer Cats Journal of LGBTQ Studies, Volume 1, Issue 1 (2015)
No Abstract
    Cover page: TRANSforming Spaces: Transgender Webcomics as a Model for Transgender Empowerment and Representation within Library and Archive Spaces
    • Thesis
    • Peer Reviewed
    UCLA Electronic Theses and Dissertations (2015)

    English Language Learner (ELL) students are the fastest growing student population within the United States. In spite of federal and state laws and regulations that require states and local districts to provide ELLs with support services, prior research has indicated that ELL students are in general lagging behind non-ELL students in academic achievement. An unanswered question is whether and how the initial designation of students as ELL (apart from their actual skill level) may influence their later academic progress and experiences. The main purpose of this study, then, was to examine the effects of initial ELL classification (while controlling for their actual skill level) on students’ academic experiences and later academic achievement. In particular, it compared outcomes for high-scoring ELL students (just below the cutoff for being classified as Initially Fluent English Speaking, IFEP) and students just above the cutoff who were classified as IFEP. This study also investigated whether students’ particular profiles of proficiency at the time of the initial classification (speaking, listening) influenced their academic experiences and achievement, as well as the experiences and achievement of students who retained their ELL status over a long term despite having initial scores placing them near the cutoff for being classified as IFEP.

    This study used student-level longitudinal data (Kindergarten through tenth grade) from a very large school district in southern California. The sample consisted of 13,335 students who were near the cutoff score of the initial CELDT (administered in Kindergarten) for distinguishing ELL from Initially Fluent English Proficient (IFEP) students. Outcomes examined included standardized test scores, course grades, and whether students enrolled in gate-keeper courses (e.g., Algebra) in the normative year (e.g., 8th grade).

    Regression discontinuity analyses showed that for students who were near the cutoff score for ELL and IFEP classification, being initially classified as ELLs was not a disadvantage. ELLs outperformed IFEPs in English Language Arts and Mathematics in early elementary grades; this difference disappeared in later grades, and the two groups showed equivalent performance. The patterns of differences and similarities between ELLs and IFEPs did not depend on whether students were more skilled in listening or speaking.

    Among students who were initially near the cutoff for being classified as ELL, students who retained their ELL classification for a long term (at least five years) showed lower academic performance and developed English proficiency more slowly than students who were reclassified as IFEP in early years (before five years.) On average, students retaining their ELL classification for a long term tended to have lower initial CELDT scores, lower parent education levels, lower attendance rates in school, a higher proportion of students who were male, and a higher proportion of students who were designated as needing special education services.

      Cover page: The Effects of English Language Learner Classification on Students’ Educational Experience and Later Academic Achievement
      • Thesis
      • Peer Reviewed
      UC Riverside Electronic Theses and Dissertations (2020)

      Interest in using optical methods in the development of noninvasive clinicaldiagnostic and therapeutic techniques for brain diseases has widely increased due to theirsimplicity, safety, and affordability. The main limitations of light-based techniques usedfor brain theranostics are the strong light scattering in the scalp and skull, which causedecrease of spatial resolution, low contrast, and small penetration depth. To address thischallenge, our group has previously introduced a transparent nanocrystallineyttria-stabilized-zirconia (nc-YSZ) cranial implant material which implant possesses themechanical strength and biocompatibility that are prerequisites for a clinically-viablepermanent cranial implant for patients.

      This implant possesses the mechanical strength and biocompatibility that areprerequisites for a clinically-viable permanent cranial implant for patients. A potentialbenefit of this optical window is an improvement of light-based therapeutic techniquesthat rely on sufficient light penetration to a target embedded in tissue such asphotobiomodulation, photodynamic therapy, and optogenetics. Another application of thisoptical window is noninvasive visualization of brain blood vessels, hematomas, and smallpathologic structures (including cancerous growth) with high resolution. This isimportant for diagnosis and treatment of many diseases such as tumors of the brain,vascular pathologies, and so forth. In this dissertation, I investigated (1) characteristicsand durability of transparent nc-YSZ implants; (2) feasibility of chronic brain imagingthrough the implant; (3) multimodal imaging across the implant to generate anarteriovenous vascular map; (4) through-scalp VIS-NIR light delivery and microvascularimaging.

        Cover page: Theranostic Window to the Brain for Multispectral Light Delivery and Microcirculation ImagingCreative Commons 'BY-NC' version 4.0 license
        • Article
        • Peer Reviewed
        UC Riverside Previously Published Works (2019)
        Since of its introduction in 1980s, laser speckle imaging has become a powerful tool in flow imaging. Its high performance and low cost made it one of the preferable imaging methods. Initially, speckle contrast measurements were the main algorithm for analyzing laser speckle images in biological flows. Speckle contrast measurements, also referred as Laser Speckle Contrast Imaging (LSCI), use statistical properties of speckle patterns to create mapped image of the blood vessels. In this communication, a new method named Laser Speckle Optical Flow Imaging (LSOFI) is introduced. This method uses the optical flow algorithms to calculate the apparent motion of laser speckle patterns. The differences in the apparent motion of speckle patterns are used to identify the blood vessels from surrounding tissue. LSOFI has better spatial and temporal resolution compared to LSCI. This higher spatial resolution enables LSOFI to be used for autonomous blood vessels detection. Furthermore, Graphics Processing Unit (GPU) based LSOFI can be used for quasi real time imaging.
          Cover page: Application of optical flow algorithms to laser speckle imaging.
          • Article
          • Peer Reviewed
          UC Riverside Previously Published Works (2018)
          Laser speckle imaging (LSI) of mouse cerebral blood flow was compared through a transparent nanocrystalline yttria-stabilized zirconia (nc-YSZ) cranial implant over time (at days 0, 14, and 28, n = 3 mice), and vs. LSI through native skull (at day 60, n = 1 mouse). The average sharpness of imaged vessels was found to remain stable, with relative change in sharpness under 7.69% ± 1.2% over 28 days. Through-implant images of vessels at day 60 appeared sharper and smaller on average, with microvessels clearly visible, compared to through-skull images where vessels appeared blurred and distorted. These results suggest that long-term imaging through this implant is feasible.
            Cover page: Evaluation of a transparent cranial implant as a permanent window for cerebral blood flow imaging.
            • Article
            • Peer Reviewed
            UC San Diego Previously Published Works (2022)
            BACKGROUND: Loss of control eating (LOC-E) in youth predicts the later development of full-syndrome binge-eating disorder (BED), and therefore, could be a relevant target for prevention treatments. To develop these treatments, it is important to understand the underlying disease processes and mechanisms. Based on the putative role of neurocognitive impairments in the pathogenesis of LOC-E, treatments that modulate these neurocognitive factors warrant further exploration. For instance, stimulants are an effective treatment for impulsivity in youth with attention deficit/hyperactivity disorder (ADHD) and have been shown to improve symptoms of BED in adults. Notably, stimulants have not been examined as a treatment for LOC-E in youth. To explore this gap, we aim to measure change in LOC-E episodes and secondary outcomes in youth with comorbid ADHD and LOC-E who are being started on stimulants. METHODS: We will collect prospective observational data on forty 8-to-13-year-old youth diagnosed with comorbid ADHD and LOC-E who are initiating a stimulant for ADHD. Prior to stimulant initiation, participants will complete baseline measures including LOC-E episode frequency in the last 3 months (primary outcome), and secondary outcomes including disordered eating cognitions, emotions and behaviors, ADHD symptom severity, parental LOC-E, impulsivity and reward sensitivity, and anxiety/mood severity. Outcome measurements will be gathered again at 3-months after initiating the stimulant. Within-patient standardized effect sizes with 95% confidence intervals will be calculated from baseline to 3-month follow-up for all outcomes. DISCUSSION: Many individuals with LOC-E or binge eating do not fully remit over the course of psychotherapy. Whereas psychotherapy may address psychological and sociocultural domains associated with LOC-E, some individuals with neurocognitive impairments (e.g., ADHD) and neurobiological deficits (e.g., low intrasynaptic dopamine or norepinephrine) may benefit from adjunctive treatment that targets those factors. This will be the first study to provide pilot data for future studies that could examine both the effect of stimulants on LOC-E in youth and underlying mechanisms. TRIAL REGISTRATION: Trial registration number: NCT05592119.
              Cover page: Effect of stimulant medication on loss of control eating in youth with attention deficit/hyperactivity disorder: a prospective, observational case series study protocol.
              • Article
              • Peer Reviewed
              UC San Diego Previously Published Works (2024)
              BOUT++ turbulence simulations were performed to investigate the impact of turbulence spreading on the edge localized mode (ELM) size and divertor heat flux width $({\lambda _q})$ broadening in small ELM regimes. This study is motivated by EAST experiments. BOUT++ linear simulations of a pedestal radial electric field (Er) scan show that the dominant toroidal number mode (n) shifts from high-n to low-n, with a narrow mode spectrum, and the maximum linear growth rate increases as the pedestal Er well deepens. The nonlinear simulations show that as the net E × B pedestal flow increases, the pressure fluctuation level and its inward penetration beyond the top of the pedestal both increase. This leads to a transition from small ELMs to large ELMs. Both inward and outward turbulence spreading are sensitive to the scrape-off-layer (SOL) plasma profiles. The inward turbulence spreading increases for the steep SOL profiles, leading to increasing pedestal energy loss in the small ELM regime. The SOL width $({\lambda _q})$ is significantly broadened progressing from the ELM-free to small ELM regime, due to the onset of strong radial turbulent transport. The extent of the SOL width $({\lambda _q})$ broadening depends strongly on outward turbulence spreading. The fluctuation energy intensity flux ${\varGamma _\varepsilon }$ at the separatrix can be enhanced by increasing either pedestal Er flow shear or local SOL pressure gradient. The ${\lambda _q}$ is broadened as the fluctuation energy intensity flux ${\varGamma _\varepsilon }$ at the last close flux surface (LCFS) increases. Local SOL E × B flow shear will restrain outward turbulence spreading and the associated heat flux width broadening. Operating in H-mode with small ELMs has the potential to solve two critical problems: reducing the ELM size and broadening the SOL width.
                • Article
                • Peer Reviewed
                UC Riverside Previously Published Works (2019)
                We report on the enhanced optical transmittance in the NIR wavelength range (900 to 2400 nm) offered by a transparent Yttria-stabilized zirconia (YSZ) implant coupled with optical clearing agents (OCAs). The enhancement in optical access to the brain is evaluated upon comparing ex-vivo transmittance measurements of mice native skull and the YSZ cranial implant with scalp and OCAs. An increase in transmittance of up to 50% and attenuation lengths of up to 2.4 mm (i.e., a five-fold increase in light penetration) are obtained with the YSZ implant and the OCAs. The use of this ceramic implant and the biocompatible optical clearing agents offer attractive features for NIR optical techniques for brain theranostics.
                  Cover page: Enhanced near infrared optical access to the brain with a transparent cranial implant and scalp optical clearing.
                  • Article
                  • Peer Reviewed
                  UC Riverside Previously Published Works (2019)

                  Background and objective

                  Microcirculation plays a critical role in physiologic processes and several disease states. Laser speckle imaging (LSI) is a full-field, real-time imaging technique capable of mapping microvessel networks and providing relative flow velocity within the vessels. In this study, we demonstrate that LSI combine with multispectral reflectance imaging (MSRI), which allows for distinction between veins and arteries in the vascular flow maps produced by LSI. We apply this combined technique to mouse cerebral vascular network in vivo, comparing imaging through the skull, to the dura mater and brain directly through a craniectomy, and through a transparent cranial "Window to the Brain" (WttB) implant.

                  Study design/materials and methods

                  The WttB implant used in this study is made of a nanocrystalline Yttria-Stabilized-Zirconia ceramic. MSRI was conducted using white-light illumination and filtering the reflected light for 560, 570, 580, 590, 600, and 610 nm. LSI was conducted using an 810 nm continuous wave near-infrared laser with incident power of 100 mW, and the reflected speckle pattern was captured by a complementary metal-oxide-semiconductor (CMOS) camera.

                  Results

                  Seven vessel branches were analyzed and comparison was made between imaging through the skull, craniectomy, and WttB implant. Through the skull, MSRI did not detect any vessels, and LSI could not image microvessels. Imaging through the WttB implant, MSRI was able to identify veins versus arteries, and LSI was able to image microvessels with only slightly higher signal-to-noise ratio and lower sharpness than imaging the brain through a craniectomy.

                  Conclusions

                  This study demonstrates the ability to perform MSRI-LSI across a transparent cranial implant, to allow for cerebral vascular networks to be mapped, including microvessels. These images contain additional information such as vein-artery separation and relative blood flow velocities, information which is of value scientifically and medically. The WttB implant provides substantial improvements over imaging through the murine cranial bone, where microvessels are not visible and MSRI cannot be performed. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.
                    Cover page: Optical Access to Arteriovenous Cerebral Microcirculation Through a Transparent Cranial Implant
                    • Article
                    • Peer Reviewed
                    UC Riverside Previously Published Works (2018)
                    Laser speckle imaging (LSI) of mouse cerebral blood flow was compared through a transparent nanocrystalline yttria-stabilized zirconia (nc-YSZ) cranial implant over time (at days 0, 14, and 28, n = 3 mice), and vs. LSI through native skull (at day 60, n = 1 mouse). The average sharpness of imaged vessels was found to remain stable, with relative change in sharpness under 7.69% ± 1.2% over 28 days. Through-implant images of vessels at day 60 appeared sharper and smaller on average, with microvessels clearly visible, compared to through-skull images where vessels appeared blurred and distorted. These results suggest that long-term imaging through this implant is feasible.
                      Cover page: Evaluation of a transparent cranial implant as a permanent window for cerebral blood flow imaging.
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