Southern California Region Research Articles

Description and Early Results of the Kaiser Permanente Southern California COVID-19 Home Monitoring Program.

The Southern California region of Kaiser Permanente developed a COVID-19 Home Monitoring program as an alternative to hospital admission to decrease hospital bed days and mitigate the adverse effects of a surge. To date, more than 15,000 patients have been enrolled and approximately 10% of enrolled patients have been escalated to hospital care for timely treatment. Our objective is to describe our COVID-19 Home Monitoring program and present early results. We conducted an observational retrospective study of all patients enrolled in the COVID-19 Home Monitoring program between April 13, 2020 through February 12, 2021. Data analysis conducted includes patient demographics, enrollment, entry points, length of stay, mortality, additional treatment, utilization, adherence, satisfaction, and alert triggers. A total of 12,461 of 13,055 patients (95.5%) recovered and completed the program, 1387 patients (10.6%) were admitted to the hospital, and 20 patients (0.2%) died while they were being monitored at home. The mortality rate at 30 days from enrollment was 1.6%. Hospital length of stay for ambulatory patients receiving oxygen only was 5.4 days compared to 3.1 days for those ambulatory patients receiving oxygen, dexamethasone, and remdesivir. COVID-19 home monitoring appears to be safe and effective. Initial data suggest it can serve as an alternative to hospitalization, decreasing hospital length of stay when patients receive therapies in the ambulatory setting otherwise reserved for the hospital. Initial results of this Home Monitoring program appear to be promising, and a longer term prospective study is warranted.

Building more housing near transit: A spatial analysis of residential densification dynamics

Although building more housing near transit has gained increasing popularity as a strategy for addressing housing unaffordability while promoting sustainability, the effectiveness of this strategy has remained unclear, particularly in auto-oriented metropolises where land use planning authority largely rests with local governments. This article provides an analysis of how parcel-level residential land use intensification takes place under the influence of public transit expansion, with explicit attention to the interactions between current and planned land use changes, in a five-county Southern California region. The analysis using a generalized structural equation modeling approach shows that residential properties are more likely to be densified in transit-rich areas. This tendency is detected not only in the existing high-quality transit areas but also in locations where transit services will be available in the future. It is also found that relaxing zoning restrictions increases the probability of parcel-level densification, and the resultant density increase can induce further zoning or plan changes in nearby areas.

Influences of Windblown Particulate Matter on Children’s Respiratory Health Residing Near the Salton Sea, California

BACKGROUND AND AIM: The production of wind-blown dust and dust storms is expected to accelerate as climate change drives land use changes and diminishes water resources. For instance, in the rural U.S./Mexico border region of the Imperial Valley, sources of wind-blown particulate matter (PM) are growing due to anthropogenic activities and the shrinking of the Salton Sea, a land-locked saline “sea” situated in the Southern California region. Residents of this environmental justice community have expressed growing concern about these environmental changes, including the health implications of worsening air quality. METHODS: To assess the impacts of PM on children’s respiratory health in a structurally marginalized community, we administered a survey to parents of elementary school children (n=456). We estimated children’s exposure to PM2.5 and PM10 using air monitoring data from governmental regional monitors based on residence at time of survey. RESULTS:22% of children reported wheeze in the past 12 months. Individual annual exposure estimates for children were on average 7.55μg/m3 (SD: 1.9) and 42.44μg/m3 (SD: 6.75) for PM2.5 and PM10, respectively. In models adjusted for age, sex, parental education, and survey language, a 1SD increase in PM10 was associated with an increased risk of wheezing in the last 12 months (OR: 1.35, 95% CI: 0.9-1.8, P=0.06). Among asthmatics, a 1SD increase in PM2.5 or PM10 was associated with an increased risk of wheezing (PM2.5 OR: 2.2, 95% CI: 1.4-3.4, P=0.0006; PM10 OR: 1.9, 95% CI: 0.9-4.0, P=0.07), and any asthma medication usage (PM2.5 OR: 1.9, 95% CI: 1.2-2.9, P=0.005; PM10 OR: 2.4, 95% CI: 1.1-4.9, P=0.01). CONCLUSIONS:These results suggest that PM2.5 and PM10 air pollution may influence children’s risk of wheezing in this rural border region. Future work aims to identify additional environmental and modifiable risk factors to facilitate implementation of targeted intervention programs to improve health. KEYWORDS: Environmental Justice, rural health, border health, respiratory health

Housing Affordability Crisis and Inequities of Land Use Change

Problem, research strategy, and findings Many fast-growing metropolitan regions face a housing affordability crisis that necessitates cities change their land use policies to address this problem. How do cities in metropolitan regions change their land use policies to equitably address the region’s housing needs? We focused on 180 cities in the Southern California region, which has a shortage of housing for all income groups and a severe shortage of affordable housing. We first examined the region-wide distribution of land uses and evaluated whether land use portfolios of cities are associated with their populations’ socioeconomic characteristics using cluster analysis and one-way analysis of variance. Next, we examined land use change by cities and measured the “weakening” (a reduction in cities’ share of residential land use for multifamily housing from 2008 to 2016) and “exclusiveness” (cities’ share of residential land use for single-family housing in 2016) of their land use portfolios. We revealed inequities in the region-wide distribution of multifamily land use, found an association between land use portfolios of cities and their populations’ socioeconomic characteristics, and thus conclude that land use change by cities inequitably addresses the region’s housing needs. We did not, however, examine the effects of land use change on housing production or affordability, which could provide further insights. Takeaway for practice Our findings suggest that a) California’s state government should require cities to reform their land use policies to mitigate the region-wide inequities in the distribution of multifamily housing and to equitably address the housing affordability crisis and b) researchers could similarly evaluate land use portfolios of cities in other metropolitan regions to suggest how to equitably address the region’s housing needs.

Expanding the Differential During the COVID-19 Pandemic: Fatal West Nile Virus Neuroinvasive Disease.

The ever-evolving pandemic of Coronavirus disease 2019 (COVID-19) has the potential to drown out other viruses continuing to infect communities. To highlight this, we present 2 cases of fatal West Nile virus neuroinvasive disease that occurred within 2 weeks of each other. Since the first positive case of West Nile virus in the United States, there have been 2 epidemics in the past 2 decades, most often occurring in regions of North Texas and Southern California, which have been areas of high-incidence for COVID-19. It is important for the health care provider to recognize diagnostic biases and maintain broad differentials for the patient presenting with fever and other symptoms associated with COVID-19.

Abstract P698: Coming Together in a Time of Distancing: Creating Community Messaging for Emergency Care During Covid

Introduction: In the early months of COVID-19 pandemic, a decline in stroke hospital admissions were reported nationwide. In a large, diverse region of Southern California, a collaborative effort was made to collect real-time data trends in stroke code activations and to assess this impact locally. The San Diego (SD) County Stroke Receiving Centers demonstrated a notable decrease of 30% in stroke code activations from March-May 2020 as compared to the same timeframe in 2019, which motivated the group to dedicate time and resources to pursue a united community messaging focused on seeking emergency treatment for stroke. Methods: A unified marketing campaign was created in collaboration with SD County EMS and the SD region American Heart Association/American Stroke Association. A single graphic message was utilized that emphasized the importance of seeking emergency treatment when suffering signs of stroke, along with the slogan “We are here for you. Every minute matters.” Impact of the campaign was gauged by quantifying the number of times our message was viewed on social media and number of stroke code activations after the campaign ended. Results: The unified social media campaign was posted by 14 of the 18 SD County stroke receiving hospitals during the month of June 2020. The team utilized Facebook, Twitter, Instagram and LinkedIn to convey the message. The campaign yielded a total of 26,727 views. The median monthly stroke code activations in July 2020 increased to 34, as compared to 26.5 for March-May 2020. Conclusion: In a time when social distancing has become the norm, it is more important than ever to band together as a community. This endeavor demonstrates that virtual messaging serves as a viable option for community education during the COVID-19 pandemic and in the future. A unified social messaging campaign targeting the importance of seeking emergency care for stroke during the COVID-19 pandemic is an effective way to reach large numbers of people regionally.

Bariatric Surgical Alterations in Tolerability, Enjoyment and Cravings in the Diet (BSATED) instrument: A new scale to measure food preferences following bariatric surgery

Bariatric surgery is associated with changing food preferences, but it is not known whether these changes differ by type of operation or are associated with weight loss. The current study presents validation results for a new 27-item scale, Bariatric Surgical Alterations in Tolerability, Enjoyment and Cravings in the Diet (BSATED). This scale measured enjoyment, craving, and intolerance changes for nine food and beverage categories common to dietary habits in the Southern California region of the U.S. one year following bariatric surgery in the Bariatric Experience Long Term (BELONG) study. Validation of BSATED was done using exploratory factor analyses, construct validity with other conceptually related survey instruments, and criterion validity using hypothesized differences for operation type and percent total weight loss (%TWL) at 12–18 months after surgery. Participants (n = 999) were 86% female, 41% non-Hispanic White, with a mean age of 43.1 ± 11.3 years and a body mass index (BMI) of 43.4 ± 6.8 kg/m2 at the time of surgery. Participants reported less enjoyment and craving for high-fat meats (62%), grains (54%), candy and other desserts (e.g. candy bars, chocolate, ice cream) (52%), and sweet baked goods (48%) 12 months after surgery. These changes were more common among participants undergoing Roux-en-Y gastric bypass (RYGB) compared to those receiving sleeve gastrectomy (SG). Participants who reported decreased enjoyment and craving for foods and beverages that post-bariatric patients are counseled to reduce or avoid had greater %TWL at 12–18 months following surgery (p < .001 and p = .003 respectively). The foods and beverages in BSATED that post-bariatric patients are counseled to reduce or avoid could be used to understand how changes in enjoyment, craving and tolerability of these foods/beverages contribute to weight loss following surgery.

Conceptualizing an Interdisciplinary Collective Impact Approach to Examine and Intervene in the Chronic Cycle of Homelessness.

Homelessness is a persistent problem in the United States in general and in Southern California especially. While progress has been made in reducing the number of people experiencing homelessness in the United States from 2007 (647,000) to 2019 (567,000), it remains an entrenched problem. The purpose of this paper is to outline a novel, interdisciplinary academic-practice partnership model to address homelessness. Where singular disciplinary approaches may fall short in substantially reducing homelessness at the community and population level, our model draws from a collective impact model which coordinates discipline-specific approaches through mutually reinforcing activities and shared metrics of progress and impact to foster synergy and sustainability of efforts. This paper describes the necessary capacity-building at the institution and community level for the model, the complementary strengths and contributions of each stakeholder discipline in the proposed model, and future goals for implementation to address homelessness in the Southern California region.

High‐Resolution Water Vapor Maps Obtained by Merging Interferometric Synthetic Aperture Radar and GPS Measurements

AbstractPrevious research has demonstrated several successful meteorological applications of interferometric synthetic aperture radar (InSAR) by mapping high‐resolution precipitable water vapor (PWV) over large areas with satisfactory precision (e.g., 1–2 mm). InSAR, however, can only measure temporal changes in the PWV, that is, the differential PWV (ΔPWV) between two SAR acquisition epochs. The construction of absolute PWV maps using InSAR observations remains an intractable problem. We present here a new method for constructing high‐resolution PWV maps by fusing InSAR and global positioning system (GPS) measurements. Our method involves: (1) extracting temporal differences in the zenith wet delays (ΔZWD) from InSAR observations with the assistance of synchronous GPS measurements, and (2) using a constrained minimum variance estimator (CMVE) to construct the high‐resolution maps of the absolute ZWDs by fusing the InSAR‐ΔZWD and the GPS‐ZWD samples, and finally (3) transforming the high‐resolution ZWDs to PWVs using an elevation‐dependent proportionality. Only a single interferogram was needed in our method, so we did not use any temporal (i.e., time‐series) hypotheses, for example, we did not assume that the average value of the temporal turbulent ZWDs was equal to zero. We validated the new method over the Southern California region using four Sentinel‐1 interferograms related to eight SAR images acquired in different seasons and in different years. We also used synchronous GPS measurements from the Southern California integrated GPS network. Eight high‐resolution maps of PWVs related to the eight SAR acquisitions were generated, covering ∼250 km in area at a ∼160 m spatial resolution. Comparisons between the CMVE method and the other two methods (GPS‐only‐based interpolation and time‐series InSAR stacking) were conducted. Experimental results showed that the CMVE method performed significantly better than conventional methods for constructing high‐resolution PWV maps, which is of great interest to a wide community of geophysicists and meteorologists.

Earthquake Prediction using Hybrid Machine Learning Techniques

This research proposes two earthquake prediction models using seismic indicators and hybrid machine learning techniques in the region of southern California. Seven seismic indicators were mathematically and statistically calculated depending on pervious recorded seismic events in the earthquake catalogue of that region. These indicators are namely, time taken during the occurrence of n seismic events (T), average magnitude of n events (M_mean), magnitude deficit that is the difference between the observed magnitude and expected one (ΔM), the curve slope for n events using inverse power law of Gutenberg Richter (b), mean square deviation for n events using inverse power law of Gutenberg Richter (η), the square root of the released energy during T time (DE1/2) and average time between events (µ). Two hybrid machine learning models are proposed to predict the earthquake magnitude during fifteen days. The first model is FPA-ELM, which is a hybrid of the flower pollination algorithm (FPA) and the extreme learning machine (ELM). The second is FPA-LS-SVM, which is a hybrid of FPA and the least square support vector machine (LS-SVM). These two models' performance is compared and assessed using four assessment criteria: Root Mean Square Error (RMSE), Mean Absolute Error (MAE), Symmetric Mean Absolute Percentage Error (SMAPE), and Percent Mean Relative Error (PMRE). The simulation results showed that the FPA-LS-SVM model outperformed the FPA-ELM, LS-SVM, and ELM models in terms of prediction accuracy.

QOL-57. SOUTHERN CALIFORNIA KAISER PERMANENTE PEDIATRIC NEURO-ONCOLOGY PROGRAM DEVELOPMENT

KEY MESSAGEStandardization of care for subspecialty patients require centralization and support across multi-disciplinary groups within the Kaiser Permanente medical group, which is a large health maintenance organization (HMO) in the United States.BACKGROUNDPrior to the development of a Pediatric Neuro-Oncology program, Southern California Kaiser Permanente pediatric neuro-oncology patients were routinely referred to respective regional academic centers for consultation. The process was not standard across the region, resulting in additional costs and differences in treatment recommendations, potentially affecting outcomes.METHODSA Pediatric Neuro-Oncology program was established, July 2017, based at the Kaiser Permanente Los Angeles Medical Center (LAMC), consisting of pediatric neuro-oncology, pediatric neurosurgery, pediatric neuro-radiology, pediatric radiation oncology, and pediatric neuro-oncology case management.RESULTSA Pediatric Neuro-Oncology tumor board was established to meet on a bi-monthly basis. Pediatric neuro-oncology patients across the Southern California now have their magnetic resonance imaging (MRI) reviewed by the same pediatric neuro radiologists. Neuropathology is standardized and sent to Children’s Hospital Los Angeles and reviewed at the molecular neuropathology tumor board attended by the pediatric neuro-oncologist. Cases discussions regarding the patients include the regional pediatric neurosurgeons, the pediatric radiation oncologists, and the pediatric neuro-oncologist, and treatment plans are recommended and recorded by the case manager.CONCLUSIONSCentralization of care has allowed for more consistent and standard care across the Southern California Region, but requires support from multi-disciplinary groups.

William E. Walton 1956–2020

William E. Walton 1956–2020

Genome-wide SNPs reveal complex fine scale population structure in the California market squid fishery (Doryteuthis opalescens)

Understanding the extent and distribution of population structure and genetic connectivity of fisheries targets are crucial for informing management. This study uses population genomics to examine patterns of genetic structure of the market squid (Doryteuthis opalescens), one of the most important commercially harvested species in California. Data from 662 single nucleotide polymorphism (SNP) loci from a total of 149 individuals representing five monthly sampling groups (May–September 2014) in the Northern (Monterey) and Southern (Southern California) regions of the fishery (n = 8) revealed no significant genetic differentiation between regions (FST = 0.008, p > 0.05, FCT = − 0.006, p > 0.05). However, discriminant analysis of principal components and pairwise comparisons of genetic differentiation revealed unexpected complex patterns of fine-scale population structure over time. These results suggest the existence of smaller potentially genetically varied micro-cohorts that continually spawn in California, as opposed to the prevailing notion that spawning occurs in two asynchronous peaks in the Northern and Southern regions of the fishery, with important implications for fisheries management.

Evaluating the U.S. Air Quality Index as a risk communication tool: Comparing associations of index values with respiratory morbidity among adults in California

BackgroundThe Air Quality Index (AQI) in the United States is widely used to communicate daily air quality information to the public. While use of the AQI has led to reported changes in individual behaviors, such behavior modifications will only mitigate adverse health effects if AQI values are indicative of public health risks. Few studies have assessed the capability of the AQI to accurately predict respiratory morbidity risks.Methods and findingsIn three major regions of California, Poisson generalized linear models were used to assess seasonal associations between 1,373,165 respiratory emergency department visits and short-term exposure to multiple metrics between 2012–2014, including: daily concentrations of NO2, O3, and PM2.5; the daily reported AQI; and a newly constructed health-based air quality index. AQI values were positively associated (average risk ratio = 1.03, 95% CI 1.02–1.04) during the cooler months of the year (November-February) in all three regions when the AQI was very highly correlated with PM2.5 (R2 ≥ 0.89). During the warm season (March-October) in the San Joaquin Valley region, neither AQI values nor the individual underlying air pollutants were associated with respiratory morbidity. Additionally, AQI values were not positively associated with respiratory morbidity in the Southern California region during the warm season, despite strong associations of the individual underlying air pollutants with respiratory morbidity; in contrast, health-based index values were observed to be significantly associated with respiratory morbidity as part of an applied policy analysis in this region, with a combined risk ratio of 1.02 (95% CI: 1.01–1.03).ConclusionsIn regions where individual air pollutants are associated with respiratory morbidity, and during seasons with relatively simple air mixtures, the AQI can effectively serve as a risk communication tool for respiratory health risks. However, the predictive ability of the AQI and any other index is contingent upon the monitored values being representative of actual population exposures. Other approaches, such as health-based indices, may be needed in order to effectively communicate health risks of air pollution in regions and seasons with more complex air mixtures.

Abstract 13550: Understanding Associations of Hospital Admission or Observation With Patient Outcomes After Emergency Department Evaluation for Suspected Acute Coronary Syndrome

Introduction: Evaluation for suspected acute coronary syndrome (ACS) results in millions of emergency department (ED) visits annually, and accounts for billions in health care costs. Understanding the benefits of hospitalization among patients who ruled out for an acute myocardial infarction (AMI) will inform physician decision making and future health care policies. Hypothesis: Hospital admission does not improve 30-day patient outcomes (death/AMI) compared to those discharged after ED evaluation for suspected ACS. Methods: We compared the effectiveness of hospitalization vs outpatient follow-up for a cohort of patients with chest pain presenting to one of 13 EDs within the Kaiser Permanente Southern California region between January 1, 2015 and December 1, 2017. The primary outcome was AMI or all-cause mortality, and secondary outcomes included revascularization and a composite MACE outcome within 30-days of ED visit. Adjusting for patient age, gender, race, ACS risk factors and chronic co-morbidities an instrumental variable (IV) analysis was used to evaluate the effect of hospitalization on patient outcomes Results: Of 77,562 chest pain patient encounters not identified as an AMI during the ED encounter, 322 (0.4%) went on to have an AMI (n=193, 0.2%) or died (n=137, 0.2%) within 30-days of ED visit (1.5% admitted vs 0.2% discharged). This included 200 (0.3%) patients who underwent coronary revascularization (0.7% admitted vs 0.2% discharged). IV analysis found no adjusted differences in 30-day patient outcomes between the hospitalized cohort and those discharged (risk reduction 0.002, 95% CI -0.002 to 0.007). Similarly, there were no differences in coronary revascularization (risk reduction 0.003, 95% CI -0.002 to 0.007). Conclusions: Among ED patients with chest pain who are not identified with an AMI, there does not appear to be a benefit in 30-day outcomes for patients who are hospitalized compared to those discharged with outpatient follow-up.

Hyperiid amphipods from the Gulf of Ulloa and offshore region, Baja California: The possible role of the gelatinous zooplankton as a transport vector into the coastal shelf waters.

Hyperiid amphipod species from the Gulf of Ulloa, Baja California, and the adjacent region (from the shelf break to 200 km offshore) were analyzed to evaluate diversity and abundances. This productive area supports small-scale commercial fisheries, including sand bass (Paralabrax nebulifer), California spiny lobster (Panulirus interruptus), abalones, clams, and others. Strong coastal upwelling events were observed during summer seasons of the period 2002–2008 between Punta Eugenia and Punta Abreojos. The upwelling plumes at Punta Abreojos are transported southward in slope waters bordering the coastal shelf of the Gulf of Ulloa, contributing to the separation of coastal and oceanic regions, and explain differences in amphipod diversity and abundances between both regions. In the offshore region, the most abundant species were Vibilia armata, Lestrigonus schizogeneios, Primno brevidens, and Eupronoe minuta, similar to previous findings in northern regions of Baja California and southern California. However, abundances of these species were lower (10–30 individuals/1000 m3), only reaching 20–50% of abundance levels reported off northern Baja California. In the coastal shelf of the Gulf of Ulloa, amphipods were virtually absent during 2002, 2003 and 2006. However, during 2004 and 2005, abundances of P. brevidens increased (54 and 20 ind/1000 m3, respectively). Moreover, during the late summer of 2007, abundances of L. schizogeneios, P. brevidens, Lycaea nasuta, Lycaea pulex, and Simorhynchotus antennarius increased considerably (261, 39, 31, 68, 416 ind/1000 m3, respectively), indicating occasional utilization of the coastal shelf by pelagic amphipods. Changes in gelatinous populations (medusae, siphonophores, ctenophores, doliolids, and salps) paralleled changes in hyperiid populations, with highest abundances in 2005–2008 in the coastal shelf. Significant correlations of 17 amphipod species with gelatinous taxa, which are often used as host organisms by hyperiid amphipods, suggest that gelatinous presence enhanced hyperiid abundance and promoted the progression of hyperiid amphipods onto the coastal shelf during parts of the 2002–2008 period.

A data-driven approach for characterizing community scale air pollution exposure disparities in inland Southern California

In 2017, Assembly Bill 617 was approved in the state of California, which mandated the allocation of resources for addressing air pollutant exposure disparities in underserved communities across the state. The bill stipulated the implementation of community scale monitoring and the development of local emissions reductions plans. We aimed to develop a streamlined, robust, and accessible PM2.5 exposure assessment approach to support environmental justice analyses. We sought to characterize individual PM2.5 exposure over multiple 24-hr periods in the inland Southern California region, which includes the underserved community of San Bernardino, CA. Personal sampling took place over five weeks in the spring of 2019, and personal PM2.5 exposure was monitored for 18 adult participants for multiple, consecutive 24-hr periods. Exposure and location data were analyzed at 5-second resolution, and participant data recovery was 50.8% on average. A spatial clustering algorithm was used to classify data points as one of seven microenvironments. Mean and median personal-ambient PM2.5 ratios were aggregated along SES lines for eligible datasets. GIS-based spatial clustering facilitated efficient microenvironment classification for more than 900,000 data points. Mean (median) personal-ambient ratios ranged from 0.26 (0.14) to 2.78 (0.65) for each microenvironment when aggregated along SES-lines. Aggregated ratios indicated that participants from the lowest SES community experienced higher home exposures compared to participants of all other communities over consecutive 24-hr monitoring periods, despite high participant mobility and relatively low variability in ambient PM2.5 during the study. The methods described here highlight the robust and accessible nature of the personal sampling campaign, which was specifically designed to reduce participant fatigue and engage members of the inland Southern California community who may experience barriers when engaging with the scientific community. This approach is promising for larger-scale, community-focused, personal exposure campaigns for direct and precise environmental justice analyses.

Optimizing Sensor Deployment and Maintenance Costs for Large-Scale Environmental Monitoring

Recent advances in low-power long-range communication schemes such as LoRa have opened up new potentials in large-scale Internet-of-Things (IoT) applications, especially environmental monitoring. However, the versatile environment and the long traveling distance have imposed significant challenges to maintenance. Previous research has shown that higher temperature exponentially accelerates electronics failure rates. The maintenance cost can take as much as 80% of the total deployment expenses if not managed carefully. In this article, we formulate a sensor deployment problem to preventively minimize maintenance costs while ensuring tolerable sensing quality and complete connectivity. We are the first to derive a maintenance cost model for IoT networks considering thermal degradation and battery depletion. To assess the spatial phenomena of interest, we adopt the sensing quality metric based on mutual information. While the proposed problem is nonconvex, we bring up a relaxed form and solve it with a sparse nonlinear optimizer. We further apply two population-based metaheuristics, i.e., particle swarm optimization (PSO) and artificial bee colony (ABC) algorithm, to approximate the optimal solution. Extensive simulations are performed on two real-world datasets of the Southern California region in the U.S. Our metaheuristics save up to 40% of maintenance cost compared with the existing greedy heuristics under the same acceptable sensing quality.

Diagenetic and Reservoir Quality Variation of Miocene Sandstone Reservoir Analogues from Three Basins of Southern California, USA

The Miocene sandstone deposits in the Southern California region are important hydrocarbon reservoirs. However, their development has been very challenging due to the wide variability in their reservoir quality. These sandstones have been studied from three sedimentary basins by petrographic thin section, scanning electron microscope, and X-ray diffraction to evaluate and compare the influence of diagenesis on their reservoir quality in these basins. Four petrofacies, namely P1 (sand injectite or dyke), P2 (sub-marine fan), P3 (turbidite and marine-influenced alluvial fans) and P4 (continental sandstones) have been identified. P1 and P2 characterise the sandstones in the San Joaquin forearc basin and are affected by kaolinite and extensive early calcite diagenesis. P3 and P4 delineate the sandstones in the Cajon Valley and Salton Trough strike-slip basins and are dominated by smectite, mixed illite-smectite, early calcite and late calcite diagenesis. Early calcite cement in P3 and P4 is in lower proportion than in P1 and P2. Although the dissolution of these sandstones by acidic fluids did not have a pattern, it, however, has the most considerable influence on P2 creating moldic pores which are expected to increase pore connectivity. The relatively abundant dissolution pores in P2, together with the absence of late authigenic calcite and illite clay in comparison to the other petrofacies studied are likely to make this sandstone facies the best reservoir targets in the Southern California region. These rocks are analogous to producing reservoirs in the region. However, because, petroleum accumulation in these reservoirs are compartmentalized by early calcite cement, maximum recovery using acidified fluids is recommended to dissolve the calcite-filled pores in order to increase connectivity of their pore network and enhance flow potential.

EVALI: A CASE SERIES ON YOUNG INDIVIDUALS DEVELOPING INTERSTITIAL PNEUMONITIS IN SOUTHERN CALIFORNIA

SESSION TITLE: Medical Student/Resident Occupational and Environmental Lung Disease SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Vaping or e-cigarettes use has been previously marketed as a safe alternative to smoking. However, the outbreak of e-cigarette, or vaping, product use-associated lung injury (EVALI) has become a public health disaster leading to the hospitalization of thousands of young, healthy individuals. Currently there is limited data available on the residual lung disease that develops after EVALI. CASE PRESENTATION: The case series included 8 patients, ages 21-46, hospitalized in the Southern California region during 2019. They presented with symptoms of unexplained dyspnea that were found to be responsive to corticosteroid treatment. All met the CDC surveillance case definition for severe pulmonary disease associated with e-cigarette use (1). DISCUSSION: The case series demonstrated heterogenous patterns of airway-centered, bronchiolocentric, interstitial pneumonia concerning for inhalation-induced lung injury. Common radiographic patterns included patchy consolidations (7/8, 87.5%), ground-glass opacification (8/8, 100%), centrilobular nodules (8/8, 100%), subpleural sparing (5/8, 62.5%), interlobular septal thickening (8/8, 100%), bronchial wall thickening (8/8, 100%), and pleural effusions (4/8, 50%). These findings of acute lung injury, including diffuse alveolar damage, organizing pneumonia and bronchiolitis were consistent with the histopathological findings recently reported by Mukhopadhyay and Butt (2,3). Radiographic findings demonstrated the presence of patchy consolidations and ground-glass opacifications in the earlier phase of disease, and the persistence of ill-defined centrilobular nodular opacifications, and the development of reticulations with traction bronchiectasis in the later phase. These radiographic patterns should be utilized in the setting of unexplained dyspnea and respiratory failure for early diagnosis and treatment of EVALI. A consistent pathologic finding was the presence of small, fine intracytoplasmic vacuoles within the foamy macrophages consistent with an endogenous source of lipids. These foamy macrophages are commonly associated with an obstructive pathology, such as small airway diseases or bronchiolitis that may present with a diffuse infiltrative pneumonia. The presence of lipid-laden macrophages should be seen as a pathological entity, and in the appropriate clinical scenario may be utilized as a sign of exposure in EVALI. CONCLUSIONS: This case series presented novel patterns of EVALI that were concerning for both alveolar damage and bronchiolar destruction. These patterns, included diffuse alveolar damage, organizing pneumonia and bronchiolitis. It also raised concerns for potential complications of EVALI, such as the development of bronchiectasis and obstructive lung diseases. We encourage physicians to discourage the use of e-cigarette products in these patients, and to maintain close follow-up for monitoring of long term sequelae of disease. Reference #1: CDC. (2020). Outbreak of Lung Injury Associated with the Use of E-Cigarette, or Vaping, Products. https://www.cdc.gov/tobacco/basic_information/e-cigarettes/severe-lung-disease.html Reference #2: Mukhopadhyay, S., Mehrad, M., Dammert, P., Arrossi, A. V., Sarda, R., Brenner, D. S., ... & Ghobrial, M. (2019). Lung Biopsy Findings in Severe Pulmonary Illness Associated With E-Cigarette Use (Vaping). American journal of clinical pathology. Reference #3: Butt, Y. M., Smith, M. L., Tazelaar, H. D., Vaszar, L. T., Swanson, K. L., Cecchini, M. J., ... & Khoor, A. (2019). Pathology of vaping-associated lung injury. New England journal of medicine, 381(18), 1780-1781. DISCLOSURES: No relevant relationships by Patrick Baghdasaryan, source=Web Response No relevant relationships by Twinkle Chandak, source=Web Response No relevant relationships by Tim Cheng, source=Web Response No relevant relationships by Matthew Crabtree, source=Web Response Industry Sponsored Research Trial relationship with PulmonX Please note: $5001 - $20000 Added 04/13/2020 by David Hsia, source=Web Response, value=Grant/Research Support Removed 04/13/2020 by David Hsia, source=Web Response Industry Sponsored Research Trial relationship with PulmonX Please note: $1001 - $5000 Added 04/13/2020 by David Hsia, source=Web Response, value=Grant/Research Support No relevant relationships by Thomas Jiang, source=Web Response No relevant relationships by Madlena Nalbandian, source=Web Response No relevant relationships by Janine Vintch, source=Web Response No relevant relationships by Fady Youssef, source=Web Response