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UCLA Previously Published Works

Cover page of Navigating Bias in Search Algorithms:  The Potential of an External Organization to Uplift Underrepresented Experiences, Quantify Harm, and Set Legal Precedents to Incentivize Ethical Change. 

Navigating Bias in Search Algorithms:  The Potential of an External Organization to Uplift Underrepresented Experiences, Quantify Harm, and Set Legal Precedents to Incentivize Ethical Change. 

(2024)

This paper delves into the multifaceted role of search algorithms in the digital landscape. While these algorithms do enhance efficiency and personalization of searching, ethical concerns arise due to inherent biases, which reinforce stereotypes and adversely affect individuals of color, women, queer people, and other minority communities. A proposed solution includes creating an external consulting-like company that can discover and quantify these biases. The biggest challenge lies in then using this to make changes within tech companies, given limited financial incentives, a lack of diversity in algorithm-building teams, and industry monopolies. To address these issues, an adjoining legal team specializing in internet anti-discrimination policy could work to set legal precedents that drive ethical changes. The discussion encompasses the organization’s viability within a capitalist society, and concludes by highlighting the broader implications of algorithmic biases across various domains, emphasizing the need for immediate, creative, and interdisciplinary solutions to address social justice issues in algorithmic decision-making.  

Cover page of The potential benefits of long-acting injectable cabotegravir in pregnant and breastfeeding women and their infants.

The potential benefits of long-acting injectable cabotegravir in pregnant and breastfeeding women and their infants.

(2024)

BACKGROUND: Pregnant and breastfeeding women (PBW) in sub-Saharan Africa have high HIV incidence rates and associated risk of vertical transmission to their infants. Oral preexposure prophylaxis (PrEP) and injectable PrEP (long-acting cabotegravir, or CAB-LA) can potentially reduce this HIV transmission, but population-level impacts are uncertain. METHODS: We extended a previously developed model of HIV and PrEP in South Africa to allow for variable PrEP duration and preference in PBW. We considered three potential scenarios for PrEP provision to PBW: oral PrEP only, CAB-LA only, and allowing oral/CAB-LA choice, with uptake and retention assumptions informed by South African data, each compared with a base scenario without PrEP for PBW. RESULTS: Without PrEP for PBW, the model estimates 1.31 million new infections will occur between 2025 and 2035 in South African adults and children, including 100 000 in PBW, 16 800 in infants at/before birth, and 35 200 in children through breastmilk. In the oral PrEP-only scenario, these numbers would reduce by 1.2% (95% CI: 0.7-1.7%), 8.6% (4.8-12.9%), 4.0% (2.1-5.8%), and 5.3% (3.0-8.2%) respectively. In the CAB-LA-only scenario, the corresponding reductions would be 6.1% (2.9-9.6%), 41.2% (19.8-65.0%), 12.6% (6.0-19.4%), and 29.5% (13.9-46.8%), respectively, and in the oral/CAB-LA choice scenario, similar reductions would be achieved [5.6% (3.4-8.0%), 39% (23.4-55.9%), 12.4% (7.4-16.8%) and 27.6% (16.5-39.9%) respectively]. CONCLUSION: CAB-LA has the potential to be substantially more effective than oral PrEP in preventing HIV acquisition in PBW and vertical transmission, and can also modestly reduce HIV incidence at a population level.

Cover page of The role of interdecadal climate oscillations in driving Arctic atmospheric river trends.

The role of interdecadal climate oscillations in driving Arctic atmospheric river trends.

(2024)

Atmospheric rivers (ARs), intrusions of warm and moist air, can effectively drive weather extremes over the Arctic and trigger subsequent impact on sea ice and climate. What controls the observed multi-decadal Arctic AR trends remains unclear. Here, using multiple sources of observations and model experiments, we find that, contrary to the uniform positive trend in climate simulations, the observed Arctic AR frequency increases by twice as much over the Atlantic sector compared to the Pacific sector in 1981-2021. This discrepancy can be reconciled by the observed positive-to-negative phase shift of Interdecadal Pacific Oscillation (IPO) and the negative-to-positive phase shift of Atlantic Multidecadal Oscillation (AMO), which increase and reduce Arctic ARs over the Atlantic and Pacific sectors, respectively. Removing the influence of the IPO and AMO can reduce the projection uncertainties in near-future Arctic AR trends by about 24%, which is important for constraining projection of Arctic warming and the timing of an ice-free Arctic.

Cover page of Circum-Antarctic bottom water formation mediated by tides and topographic waves.

Circum-Antarctic bottom water formation mediated by tides and topographic waves.

(2024)

The downslope plumes of dense shelf water (DSW) are critical for the formation of Antarctic Bottom Water (AABW), and thus to the exchange of heat and carbon between surface and abyssal ocean. Previous studies have shown that tides and overflow-forced topographic Rossby waves (TRWs) may have strong impact on the downslope transport of DSW, but it remains unclear how the combined action of these two processes influence the descent processes of DSW, and of the resulting AABW properties. Here, with a synthesis of historical in situ observations and a set of numerical model experiments, we show that tides and TRWs play comparable roles in AABW formation: they both act to accelerate DSW descent to the abyss, leading to the formation of colder and denser AABW. Yet, tides have little impact on AABW formation unless the continental slope is steep enough to suppress TRW generation. We further characterize the dynamical regimes of dense overflows around the entire Antarctic continent based on the relative importance of TRWs versus tides. These findings highlight the pervasive role of high-frequency processes, which are not well represented in the present climate models, in the formation of AABW, and thus in the global overturning circulation.

Cover page of Percutaneous cholecystostomy tube placement as a bridge to cholecystectomy for grade III acute cholecystitis: A national analysis.

Percutaneous cholecystostomy tube placement as a bridge to cholecystectomy for grade III acute cholecystitis: A national analysis.

(2024)

INTRODUCTION: Percutaneous cholecystostomy (PCT) is an alternative to cholecystectomy (CCY) in high-risk surgical candidates with severe acute cholecystitis. A subset of these patients ultimately undergo delayed CCY. We therefore compared outcomes of delayed CCY in patients with grade III acute cholecystitis who received a PCT on index admission, to those who did not. METHODS: Non-elective adult hospitalizations for grade III acute cholecystitis that underwent delayed CCY were identified in the 2016-2020 Nationwide Readmission Database. Patients who received a PCT during their index admission comprised the PCT group (others: Non-PCT). Outcomes were assessed for the CCY hospitalization. Entropy balancing was used to generate sample weights to adjust for differences in baseline characteristics. Regression models were created to evaluate the association between PCT and the outcomes of interest. RESULTS: Of an estimated 13,782 patients, 13.3 % comprised PCT. Compared to Non-PCT, PCT were older (71.1 ± 13.1 vs 67.4 ± 15.3 years) and more commonly in the highest income quartile (22.5 vs 16.1 %, both p < 0.001). After risk adjustment, PCT was associated with reduced odds of respiratory (AOR 0.67, CI 0.54-0.83) and infectious (AOR 0.77, CI 0.62-0.96) complications after eventual CCY. Finally, PCT had comparable pLOS (β +0.31, CI [-0.14, 0.77]) and operative hospitalization costs (β $800, CI [-2300, +600]). CONCLUSION: In the present study, PCT was associated with decreased odds of perioperative complications and comparable resource utilization upon readmission CCY. Our findings suggest that PCT may be helpful in bridging patients with grade III acute cholecystitis to eventual CCY.

Cover page of Associations between anemia and FGF23 in the CKiD study.

Associations between anemia and FGF23 in the CKiD study.

(2024)

BACKGROUND: Fibroblast growth factor 23 (FGF23) is a bone-derived hormone that plays a central role in chronic kidney disease-mineral bone disorder and is associated with CKD progression and cardiovascular morbidity. Factors related to CKD-associated anemia, including iron deficiency, can increase FGF23 production. This study aimed to assess whether anemia and/or iron deficiency are associated with increased circulating concentrations of FGF23 in the large, well-characterized Chronic Kidney Disease in Children (CKiD) study cohort. METHODS: Hemoglobin concentrations, iron parameters, C-terminal (total) FGF23, intact FGF23, and relevant covariables were measured in cross-sectional analysis of CKiD study subjects. RESULTS: In 493 pediatric patients with CKD (median [interquartile range] age 13 [9, 16] years), the median estimated glomerular filtration rate was 48 [35, 61] ml/min/1.73 m2, and 103 patients (21%) were anemic. Anemic subjects had higher total FGF23 concentrations than non-anemic subjects (204 [124, 390] vs. 109 [77, 168] RU/ml, p < 0.001). In multivariable linear regression modeling, anemia was independently associated with higher total FGF23, after adjustment for demographic, kidney-related, mineral metabolism, and inflammatory covariables (standardized β (95% confidence interval) 0.10 (0.04, 0.17), p = 0.002). In the subset of subjects with available iron parameters (n = 191), iron deficiency was not associated with significantly higher total FGF23 concentrations. In the subgroup that had measurements of both total and intact FGF23 (n = 185), in fully adjusted models, anemia was significantly associated with higher total FGF23 (standardized β (95% CI) 0.16 (0.04, 0.27), p = 0.008) but not intact FGF23 (standardized β (95% CI) 0.02 (-0.12, 0.15), p = 0.81). CONCLUSIONS: In this cohort of pediatric patients with CKD, anemia was associated with increased total FGF23 levels but was not independently associated with elevated intact FGF23, suggesting possible effects on both FGF23 production and cleavage. Further studies are warranted to investigate non-mineral factors affecting FGF23 production and metabolism in CKD.

Cover page of Comparison of patient-reported outcomes measurement information system (PROMIS®)-29 and PROMIS global physical and mental health scores.

Comparison of patient-reported outcomes measurement information system (PROMIS®)-29 and PROMIS global physical and mental health scores.

(2024)

PURPOSE: The Patient-Reported Outcomes Measurement and Information System (PROMIS®): includes the PROMIS-29 physical and mental health summary and the PROMIS global physical and mental health scores. It is unknown how these scores coincide with one another. This study examines whether the scores yield similar or different information. METHODS: The PROMIS-29 and the PROMIS global health items were administered to 5804 adults from Amazons Mechanical Turk (MTurk) in 2021-2022 and to 4060 adults in the Ipsos KnowledgePanel (KP) in 2022. RESULTS: The median age of those in MTurk (KP) was 36 (54) and 53% (50%) were male. Mean T-scores on the PROMIS-29 and PROMIS global physical health scales were similar, but PROMIS global mental health was 3-4 points lower than the PROMIS-29 mental health summary score. Product-moment correlations ranged from 0.69 to 0.81 between the PROMIS-29 physical health and PROMIS global physical health scales and 0.56-0.69 between the mental health scales. Multi-trait multimethod analyses indicated that only a small proportion of the correlations between the two methods of measuring mental health were significantly more highly correlated with one another than correlations between physical and mental health. CONCLUSIONS: PROMIS-29 and PROMIS global mental health scales provide different information and, therefore, study conclusions may vary depending on which measure is used. Interpretation of results needs to consider that the PROMIS-29 mental health scale is a weighted combination of specific domains while the PROMIS global mental health scale is based on general mental health perceptions. Further comparisons of methods of assessing mental health are needed.

Cover page of Endothelial Glycocalyx Degradation Patterns in Sepsis-Associated Pediatric Acute Respiratory Distress Syndrome: A Single Center Retrospective Observational Study.

Endothelial Glycocalyx Degradation Patterns in Sepsis-Associated Pediatric Acute Respiratory Distress Syndrome: A Single Center Retrospective Observational Study.

(2024)

BACKGROUND: Sepsis-associated destruction of the pulmonary microvascular endothelial glycocalyx (EGCX) creates a vulnerable endothelial surface, contributing to the development of acute respiratory distress syndrome (ARDS). Constituents of the EGCX shed into circulation, glycosaminoglycans and proteoglycans, may serve as biomarkers of endothelial dysfunction. We sought to define the patterns of plasma EGCX degradation products in children with sepsis-associated pediatric ARDS (PARDS), and test their association with clinical outcomes. METHODS: We retrospectively analyzed a prospective cohort (2018-2020) of children (≥1 month to <18 years of age) receiving invasive mechanical ventilation for acute respiratory failure for ≥72 h. Children with and without sepsis-associated PARDS were selected from the parent cohort and compared. Blood was collected at time of enrollment. Plasma glycosaminoglycan disaccharide class (heparan sulfate, chondroitin sulfate, and hyaluronan) and sulfation subtypes (heparan sulfate and chondroitin sulfate) were quantified using liquid chromatography tandem mass spectrometry. Plasma proteoglycans (syndecan-1) were measured through an immunoassay. RESULTS: Among the 39 mechanically ventilated children (29 with and 10 without sepsis-associated PARDS), sepsis-associated PARDS patients demonstrated higher levels of heparan sulfate (median 639 ng/mL [interquartile range, IQR 421-902] vs 311 [IQR 228-461]) and syndecan-1 (median 146 ng/mL [IQR 32-315] vs 8 [IQR 8-50]), both p = 0.01. Heparan sulfate subtype analysis demonstrated greater proportions of N-sulfated disaccharide levels among children with sepsis-associated PARDS (p = 0.01). Increasing N-sulfated disaccharide levels by quartile were associated with severe PARDS (n = 9/29) with the highest quartile including >60% of the severe PARDS patients (test for trend, p = 0.04). Higher total heparan sulfate and N-sulfated disaccharide levels were independently associated with fewer 28-day ventilator-free days in children with sepsis-associated PARDS (all p < 0.05). CONCLUSIONS: Children with sepsis-associated PARDS exhibited higher plasma levels of heparan sulfate disaccharides and syndecan-1, suggesting that EGCX degradation biomarkers may provide insights into endothelial dysfunction and PARDS pathobiology.

Cover page of Adapting E-cigarette prevention programming to reach the latinx community

Adapting E-cigarette prevention programming to reach the latinx community

(2024)

Purpose

E-cigarettes are the most commonly used tobacco product among youth in the United States. Yet evidence-based prevention programming is limited due to the rapid onset of this threat. Community-based efforts to address vaping largely target youth in school settings. Although parents can play an important role in youth tobacco control efforts, messages about the dangers of vaping, use among adolescents, and strategies for intervening have not reached many Spanish-speaking parents in low-income Latinx communities. Our community-academic team developed e-cigarette prevention programming for use by promotor/as de salud to address this unmet need.

Methods

During the 1-year project, the team worked closely with a Project Advisory Committee to: review existing evidence-informed materials; conduct focus groups with parents, youth and promotor/as to guide program development; develop a curriculum to prepare promotor/as to educate low-literacy, Spanish-speaking parents about vaping; craft Spanish language resources for promotor/as to use in community education sessions; train 61 promotor/as to deliver the program; and support program delivery to 657 community members.

Results

Focus groups with promotor/as and community members, key-informant interviews, and brief surveys informed program development and assessment. Community member feedback was essential to development of appropriate materials. Promotor/as demonstrated significant pre- to post- training increases in e-cigarette knowledge and confidence in delivering vaping prevention education. Community members demonstrated a mastery of basic e-cigarette concepts and expressed intention to discuss vaping with their children.

Conclusions

Promotor/a-led programming for parents represents a promising approach to vaping prevention and control in the Latinx community.