Disparate Patterns Research Articles

Disparate statin prescribing following hospital discharge for stroke or transient ischemic attack: Findings from COMPASS.

Published guidelines recommend high-intensity statins following an ischemic stroke or transient ischemic attack (TIA). The authors examined the potential for disparate patterns of statin prescribing in a cluster randomized trial of transitional care following acute stroke or TIA. Medications taken before hospitalization and statins prescribed at discharge among stroke and TIA patients at 27 participating hospitals were examined. Any statin and intensive statin prescribed at discharge were compared by age (<65, 65-75, >75 years), racial category (White vs. Black), sex (male vs. female), and rurality (urban vs. non-urban) using logistic mixed models. Among 3211 patients (mean age 67 years; 47% female; 29% Black), 90% and 55%, respectively, were prescribed any statin or intensive statin therapy at discharge. White (vs. Black) patients (0.71, 0.51-0.98) less commonly received any statin prescription, while stroke (vs. TIA) patients (1.90, 1.38-2.62) and those residing in urban areas (1.66, 1.07-2.55) more commonly received any statin prescription. Among those prescribed a statin, only 42% of White and 51% of Black patients >75 years. were prescribed an intensive statin; the OR for intensive statin prescribing was 0.44 for patients >75 years and was similar in a subgroup not on a statin previously. Following stroke or TIA, statin prescribing remains lower in White patients, in those with TIA, and in those in non-urban areas. Intensive statin prescribing remains limited, particularly in patients >75 years. These data may inform efforts to improve guideline concordant prescribing for post-stroke patients.

Timing matters: Sex differences in inflammatory and behavioral outcomes following repetitive blast mild traumatic brain injury

BackgroundRepetitive blast-related mild traumatic brain injury (mTBI) caused by exposure to high explosives is increasingly common among warfighters as well as civilians. While women have been serving in military positions with increased risk of blast exposure since 2016, there are few published reports examining sex as a biological variable in models of blast mTBI, greatly limiting diagnosis and treatment capabilities. As such, here we examined outcomes of repetitive blast trauma in female and male mice in relation to potential behavioral, inflammatory, microbiome, and vascular dysfunction at multiple timepoints. MethodsIn this study we utilized a well-established blast overpressure model to induce repetitive (3x) blast-mTBI in both female and male mice. Acutely following repetitive exposure, we measured serum and brain cytokine levels, blood–brain barrier (BBB) disruption, fecal microbial abundance, and locomotion and anxiety-like behavior in the open field assay. At the one-month timepoint, in female and male mice we assessed behavioral correlates of mTBI and PTSD-related symptoms commonly reported by Veterans with a history of blast-mTBI using the elevated zero maze, acoustic startle, and conditioned odorant aversion paradigms. ResultsRepetitive blast exposure resulted in both similar (e.g., increased IL-6), and disparate (e.g., IL-10 increase only in females) patterns of acute serum and brain cytokine as well as gut microbiome changes in female and male mice. Acute BBB disruption following repetitive blast exposure was apparent in both sexes. While female and male blast mice both exhibited acute locomotor and anxiety-like deficits in the open field assay, only male mice exhibited adverse behavioral outcomes that lasted at least one-month. DiscussionRepresenting a novel survey of potential sex differences following repetitive blast trauma, our results demonstrate unique similar yet divergent patterns of blast-induced dysfunction in female vs. male mice and highlight novel targets for future diagnosis and therapeutic development.

Does the Disparity Patterning Differ between Diagnosed and Undiagnosed Hypertension among Adults? Evidence from Indonesia.

Healthcare systems in many low- and middle-income countries (LMICs) are not yet designed to tackle the high and increasing burden of non-communicable diseases (NCDs), including hypertension. As a result, a large proportion of people with disease or risk factors are undiagnosed. Policymakers need to understand the disparity better to act. However, previous analyses on the disparity in undiagnosed hypertension, especially from LMICs, are lacking. Our study assessed the geographic and socioeconomic disparity in undiagnosed hypertension and compared it with diagnosed hypertension. We used the Basic Health Survey (Riskesdas) 2018 and performed geospatial and quantitative analyses across 514 districts in Indonesia. Dependent variables included diagnosed and undiagnosed hypertension among adults (18+ years) and by gender. A high prevalence of undiagnosed hypertension at 76.3% was found, with different patterns of disparity observed between diagnosed and undiagnosed hypertension. Diagnosed hypertension was 1.87 times higher in females compared with males, while undiagnosed hypertension rates were similar between genders. Urban areas had up to 22.6% higher rates of diagnosed hypertension, while undiagnosed hypertension was 11.4% more prevalent among females in rural areas. Districts with higher education rates had up to 25% higher diagnosed hypertension rates, while districts with lower education rates had 6% higher rates of undiagnosed hypertension among females. The most developed regions had up to 76% and 40% higher prevalence of both diagnosed and undiagnosed hypertension compared with the least developed regions. The disparity patterning differs between diagnosed and undiagnosed hypertension among adults in Indonesia. This highlights the need for effective measures, including healthcare system reforms to tackle NCDs in LMICs.

Contrasting patterns of disparity suggest differing constraints on the evolution of trilobite cephalic structures during the Cambrian ‘explosion’

AbstractTrilobites are an abundant group of Palaeozoic marine euarthropods that appear abruptly in the fossil recordc. 521 million years ago. Quantifying the development of morphological variation (or ‘disparity’) through time in fossil groups like trilobites is critical in understanding evolutionary radiations such as the Cambrian ‘explosion’. Here, I use geometric morphometrics to quantify ‘cumulative disparity’ in functionally‐important structures within the trilobite cephalon across their initial radiation during Cambrian Series 2. Overall cephalic disparity increased rapidly and attained a maximum within several million years. This pattern is dominated by the cephalic outline (in particular the genal spines), reflecting rapid, convergent expansion to the extremes of morphospace in a few early families. In contrast, removing the outline and focusing on structures such as the glabella and eye ridges (associated with feeding and vision, respectively) showed a more gradual increase in disparity, closer in line with taxonomic diversity and supporting the hypothesis of a relatively accurate trilobite fossil record. These contrasting patterns suggest that disparity in different structures was constrained in different ways, with extrinsic (ecological) factors probably having the major impact on overall disparity. It also implies that patterns of disparity in isolated substructures cannot necessarily be taken individually as representative of overall morphologies.

Effect of varying shear rates at different resting times on the rheology of 3D printable concrete

3D printing offers a paradigm shift in the construction industry. The material undergoes different stages like mixing, pumping, extruding, and printing with disparate shearing patterns and the effect of shear rates must be brought into consideration. The rheological properties of 3D printable concrete with varying shear rates at different resting times were studied. The designed mix has an ultra-high compressive strength of 110 MPa. Different hystresis curves with shear rates of 0–25 s−1 (P1) and 0–50 s−1 (P2) are studied. The tests were conducted at 10 min intervals up to 30 min resting time. The experimental down flow curves are further analyzed using the Bingham model, the modified Bingham model, and the Herschel-Bulkley model. It is observed that the rheological properties of 3D printable concrete are highly dependent on the resting time, and the applied shear rates and demand judicious selection of rheological models to predict yield stress and plastic viscosity. The comparison between experimental and analytical models indicates better predictability with the modified Bingham and Herschel- Bulkley model. The yield stress values for the modified Bingham model were found to be varying from 95 Pa to 178 Pa and Herschel-Bulkley model from 130 Pa to 177 Pa for P1 and P2, respectively.

Disparate continental scale patterns in floral host breadth of Australian colletid bees (Colletidae: Hymenoptera)

Plant-bee networks are rarely, if ever, studied quantitatively at continental scales, yet these have the potential to inform how biota and ecosystems are assembled beyond narrower regional biomes. The short-tongued bee family Colletidae comprises the major component of bee diversity in Australia, with three key subfamilies: the Neopasiphaeinae, Hylaeinae, and Euryglossinae. We use museum data (> 27,000 records) to record binary interactions between these bees (from each of these subfamilies, resolved to subgenera) and plants (resolved to genera). The resulting networks were analysed using bipartite graphs and associated indices of network structure. The three bee subfamilies showed markedly different network structures with their floral hosts. Euryglossinae had strong interactions with Myrtaceae and an otherwise relatively narrow host breadth, Neopasiphaeinae had little signal of host specialisation above genera and a very broad host breadth, and Hylaeinae appeared intermediate in network structure. Furthermore, Euryglossinae is more speciose within Australia (404 species, or ~ 25% of described Australian bee fauna) than Hylaeinae and Neopasiphaeinae, but these differences do not correspond to the stem ages of the three subfamilies, suggesting that time-since-origin does not explain bee species diversity or floral host breadth. Patterns of host breadth persist after rarefaction analyses that correct for differing numbers of observation records. We suggest that visitation networks could be influenced by evolutionary constraints to expansion of floral host breadth, but it is also possible that many bee-plant interactions are shaped by bees exploiting floral traits that are driven by non-bee fauna operating at large biogeographical scales.

Acute Ostracism-Related Pain Sensitization in the Context of Accumulated Lifetime Experiences of Ostracism

Ostracism (ie, being ignored/excluded) is a form of social adversity that powerfully impacts health and well-being. While laboratory research indicates that experimentally manipulated experiences of ostracism impact pain, findings have been mixed. Prior investigations have not considered moderating or main effects of individual histories of ostracism, and have been limited in the scope of their pain testing. In this study, participants without current pain reported lifetime experiences of ostracism prior to a laboratory visit where they were randomized to experience either a single episode of ostracism (ie, acute ostracism) or control condition that was immediately followed by quantitative sensory testing. Results indicate that the experimental effect of a single episode of ostracism on pain ratings, after-sensations, and temporal summation of pain is moderated by lifetime ostracism; no main effects were found. For individuals with histories of more lifetime ostracism, encountering a single episode of ostracism led to greater pain sensitization relative to the control condition, whereas no experimental effect was observed for individuals with little lifetime exposure to ostracism. These findings indicate that acute experiences of ostracism may be accompanied by periods of hyperalgesia for people who are chronically ostracized, implicating ostracism as a potential social moderator of pain sensitization. People who are stigmatized may therefore experience enhanced pain burden with repeated and accumulating experiences of ostracism. PerspectiveResults suggest that in the context of accumulated lifetime experiences of ostracism, single experiences of ostracism evoke central sensitization. In this way, ostracism may function to trigger central sensitization and shape socially- and societally-determined patterns of pain burden and disparity.

Morphospace trends underlying a global turnover: Ecological dynamics of trilobite assemblages at the onset of the Ordovician Radiation

The early Palaeozoic was an interval of critical importance in the history of life as it records major events such as the Cambrian Explosion and the Ordovician Radiation. Analyses of macroevolutionary and macroecological dynamics explored from a morphospace perspective at different scales and from a palaeoecological viewpoint remain scarce. In this contribution we show the potential power that morphospace analysis can bring to the study of the ecological context of radiations. For this we focus on important trilobite assemblages ranging from the late Cambrian - Early Ordovician of the Argentine Cordillera Oriental. We calculated trilobite disparity through seven time bins that encompass the Furongian, Tremadocian and the Floian. Our results show a hierarchical structure in disparity patterns, where regional disparity is modulated by its beta component during the Furongian – lower Tremadocian, changing towards the Floian where alpha disparity becomes a stronger contributor. These trends reveal a shift in the assembly of regional disparity, modulated by the way local coexistence is controlled. Additionally, the temporal decoupling recorded in diversity and disparity trends can be related to the way these patterns are structured across the ecological hierarchy. This coincides with moments of high compositional turnover, congruent with the timing of transition between trilobite evolutionary faunas (TEFs) at a global scale. Peaks in regional disparity are related to the sum of these faunas contributing high values rather than to a growing disparity of the successive TEFs, suggesting that the rise in disparity is due to the coexistence of evolutionary faunas. Regional-scale dynamics described herein coupled with previous evidence regarding global patterns allow us to consider that the transition between trilobite evolutionary faunas was mainly related to increasing niche differentiation, followed by an increase in dispersal. These results suggest a context of higher ecological complexity than previously envisaged for the early stages of the Ordovician Radiation.

Evolution of COVID-19 Health Disparities in Arizona.

COVID-19 burdens are disproportionally high in underserved and vulnerable communities in Arizona. As the pandemic progressed, it is unclear if the initial associated health disparities have changed. This study aims to elicit the dynamic landscape of COVID-19 disparities at the community level and identify newly emerging vulnerable subpopulations. Findings from this study can inform interventions to increase health equity among minoritized communities in the Southwest, other regions of the US, and globally. We compiled biweekly COVID-19 case counts of 274 zip code tabulation areas (ZCTAs) in Arizona from October 21, 2020, to November 25, 2021, a time spanning multiple waves of COVID-19 case growth. Within each biweekly period, we tested the associations between the growth rate of COVID-19 cases and the population composition in a ZCTA including race/ethnicity, income, employment, and age using multiple regression analysis. We then compared the associations across time periods to discover temporal patterns of health disparities. The association between the percentage of Latinx population and the COVID-19 growth rate was positive before April 2021 but gradually converted to negative afterwards. The percentage of Black population was not associated with the COVID-19 growth rate at the beginning of the study but became positive after January 2021 which persisted till the end of the study period. Young median age and high unemployment rate emerged as new risk factors around mid-August 2021. Based on these findings, we identified 37 ZCTAs that were highly vulnerable to future fast escalation of COVID-19 cases. As the pandemic progresses, vulnerabilities associated with Latinx ethnicity improved gradually, possibly bolstered by culturally responsive programs in Arizona to support Latinx. Still communities with disadvantaged social determinants of health continued to struggle. Our findings inform the need to adjust current resource allocations to support the design and implementation of new interventions addressing the emerging vulnerabilities at the community level.

Stage of infection with Mycobacterium avium subsp. paratuberculosis impacts expression of Rab5, Rab7, and CYP27B1 in macrophages within the ileum of naturally infected cows.

Macrophages are the preferential target of Mycobacterium avium subsp. paratuberculosis (MAP), the etiologic agent of ruminant paratuberculosis. Uptake of pathogens by intestinal macrophages results in their trafficking through endosomal compartments, ultimately leading to fusion with an acidic lysosome to destroy the pathogen. MAP possesses virulence factors which disrupt these endosomal pathways. Additionally, levels of serum vitamin D3 have proven relevant to host immunity. Dynamics of endosomal trafficking and vitamin D3 metabolism have been largely unexplored in bovine paratuberculosis. This study aimed to characterize expression of early and late endosomal markers Rab5 and Rab7, respectively, within CD68+ macrophages in frozen mid-ileum sections harvested from cows at different stages of natural paratuberculosis infection. Additionally, factors of vitamin D3 signaling and metabolism were characterized through expression of vitamin D3 activating enzyme 1α-hydroxylase (CYP27B1), vitamin D3 inactivating enzyme 24-hydroxylase (CYP24A1), and vitamin D3 receptor (VDR) within CD68+ ileal macrophages. Cows with clinical paratuberculosis had significantly greater macrophage and MAP burden overall, as well as intracellular MAP. Total expression of Rab5 within macrophages was reduced in clinical cows; however, Rab5 and MAP colocalization was significantly greater in this group. Intracellular Rab7 colocalization with MAP was not detected in subclinical or Johne's Disease negative (JD-) control cows but was present in clinical cows. Additionally, macrophage CYP27B1 expression was significantly reduced in clinical cows. Taken together, the results from this study show disparate patterns of expression for key mediators in intracellular MAP trafficking and vitamin D metabolism for cows at different stages of paratuberculosis.

Real-World Diabetes Technology: Overcoming Barriers and Disparities.

Real-World Diabetes Technology: Overcoming Barriers and Disparities.

Latitudinal variation and plasticity in response to temperature in Geukensia demissa.

As global temperatures warm, species must adapt to a changing climate or transition to a different location suitable for their survival. Understanding the extent to which species are able to do so, particularly keystone species, is imperative to ensuring the survival of key ecosystems. The ribbed mussel Geukensia demissa is an integral part of salt marshes along the Atlantic coast of North America. Spatial patterns of genomic and phenotypic divergence have been previously documented, although their link with coastal environmental variation is unknown. Here, we study how populations of G. demissa in the northern (Massachusetts) and southern (Georgia) portions of the species range respond to changes in temperature. We combine assays of variation in oxygen consumption and RNA transcriptomic data with genomic divergence analyses to identify how separate populations of G. demissa may vary in distinct thermal environments. Our results show differences in constitutive oxygen consumption between mussels from Georgia and Massachusetts, as well as shared and disparate patterns of gene expression across temperature profiles. We also find that metabolic genes seem to be a strong component of divergence between these two populations. Our analysis highlights the importance of studying integrative patterns of genomic and phenotypic variation in species that are key for particular ecosystems, and how they might respond to further changes in climate.

Allopatric mosaics in the Indo-West Pacific crab subfamily Chlorodiellinae reveal correlated patterns of sympatry, genetic divergence, and genitalic disparity

Molecular studies have revealed that many species once thought to be wide-ranging in the Indo-West Pacific contain allopatric mosaics of endemic lineages. These lineages provide compelling evidence that substantial time is needed to evolve isolating mechanisms sufficient to permit successful secondary sympatry, and that divergence is initiated in allopatry. In this context, questions arise regarding the nature, timing, and origin of isolating mechanisms that permit secondary sympatry. We present a phylogeny of the crab subfamily Chlorodiellinae which displays allopatric mosaics within species. These allopatric lineages typically do not have divergent male genitalia, while older sympatric lineages do. We tested the relationship between genetic distance (proxy for time), sympatry, and the divergence of male genitalic morphology. Our results suggest that male genitalic divergence is not involved in the initiation of speciation in chlorodielline crabs, having likely occurred only after isolation began in allopatry. However, morphological evolution of genitalia seemingly does play an important role in completing the process of speciation in these crabs.

The Statistics of Eye Movements and Binocular Disparities during VR Gaming: Implications for Headset Design.

The human visual system evolved in environments with statistical regularities. Binocular vision is adapted to these such that depth perception and eye movements are more precise, faster, and performed comfortably in environments consistent with the regularities. We measured the statistics of eye movements and binocular disparities in virtual-reality (VR) - gaming environments and found that they are quite different from those in the natural environment. Fixation distance and direction are more restricted in VR, and fixation distance is farther. The pattern of disparity across the visual field is less regular in VR and does not conform to a prominent property of naturally occurring disparities. From this we predict that double vision is more likely in VR than in the natural environment. We also determined the optimal screen distance to minimize discomfort due to the vergence-accommodation conflict, and the optimal nasal-temporal positioning of head-mounted display (HMD) screens to maximize binocular field of view. Finally, in a user study we investigated how VR content affects comfort and performance. Content that is more consistent with the statistics of the natural world yields less discomfort than content that is not. Furthermore, consistent content yields slightly better performance than inconsistent content.

Decoupled Patterns of Diversity and Disparity Characterize an Ecologically Specialized Lineage of Neotropical Cricetids

Decoupled Patterns of Diversity and Disparity Characterize an Ecologically Specialized Lineage of Neotropical Cricetids

Racial and ethnic disparities in Medicare Part D medication therapy management services utilization

BackgroundThe Medicare Part D medication therapy management (MTM) program has positive effects on medication and health service utilization. However, little is known about its utilization, much less so about the use among racial and ethnic minorities. ObjectiveTo examine MTM service utilization among older Medicare beneficiaries and to identify any racial and ethnic disparity patterns. MethodsA retrospective cross-sectional analysis of 2017 Medicare administrative data, linked to the Area Health Resources Files. Fourteen outcomes related to MTM service nature, initiation, quantity, and delivery were examined using logistic, negative binomial, and Cox proportional hazards regression models. ResultsRacial and ethnic disparities were found with varying patterns across outcomes. For example, compared with White patients, the odds of opting out of MTM were 8% higher for Black patients (odds ratio [OR] = 1.08, 95% confidence interval [CI] = 1.03–1.14), 57% higher for Hispanic patients (OR = 1.57, 95% CI = 1.42–1.72), and 57% higher for Asian patients (OR = 1.57, 95% CI = 1.33–1.85). The odds of continuing MTM from the previous years were 12% lower for Black patients (OR = 0.88, 95% CI = 0.86–0.90) and 3% lower for other patients (OR = 0.97, 95% CI = 0.95–0.99). In addition, the probability of being offered a comprehensive medication review (CMR) after MTM enrollment was 9% lower for Hispanic patients (hazard ratio [HR] = 0.91, 95% CI = 0.85–0.97), 9% lower for Asian patients (HR = 0.91, 95% CI = 0.87–0.94), and 3% lower for other patients (HR = 0.97, 95% CI = 0.95–0.99). Hispanic and Asian patients were more likely to have someone other than themselves receive a CMR. ConclusionsRacial and ethnic disparities in MTM service utilization were identified. Although the disparities in specific utilization outcomes vary across racial/ethnic groups, it is evident that these disparities exist and may result in vulnerable communities not fully benefiting from the MTM services. Causes of the disparities should be explored to inform future reform of the Medicare Part D MTM program.

Disparities in Fertility-Sparing Treatment and Use of Assisted Reproductive Technology After a Diagnosis of Cervical, Ovarian, or Endometrial Cancer.

To assess the presence of sociodemographic and clinical disparities in fertility-sparing treatment and assisted reproductive technology (ART) use among patients with a history of cervical, endometrial, or ovarian cancer. We conducted a population-based cohort study of patients aged 18-45 years who were diagnosed with cervical cancer (stage IA, IB), endometrial cancer (grade 1, stage IA, IB), or ovarian cancer (stage IA, IC) between January 1, 2000, and December 31, 2015, using linked data from the CCR (California Cancer Registry), the California Office of Statewide Health Planning and Development, and the Society for Assisted Reproductive Technology. The primary outcome was receipt of fertility-sparing treatment , defined as surgical or medical treatment to preserve the uterus and at least one ovary. The secondary outcome was fertility preservation , defined as ART use after cancer diagnosis. Multivariable logistic regression analysis was used to estimate odds ratios and 95% CIs for the association between fertility-sparing treatment and exposures of interest: age at diagnosis, race and ethnicity, health insurance, socioeconomic status, rurality, and parity. We identified 7,736 patients who were diagnosed with cervical, endometrial, or ovarian cancer with eligible histology. There were 850 (18.8%) fertility-sparing procedures among 4,521 cases of cervical cancer, 108 (7.2%) among 1,504 cases of endometrial cancer, and 741 (43.3%) among 1,711 cases of ovarian cancer. Analyses demonstrated nonuniform patterns of sociodemographic disparities by cancer type for fertility-sparing treatment, and ART. Fertility-sparing treatment was more likely among young patients, overall, and of those in racial and ethnic minority groups among survivors of cervical and ovarian cancer. Use of ART was low (n=52) and was associated with a non-Hispanic White race and ethnicity designation, being of younger age (18-35 years), and having private insurance. This study demonstrates that clinical and sociodemographic disparities exist in the receipt of fertility-sparing treatment and ART use among patients with a history of cervical, endometrial, or ovarian cancer.

Measurement and spatiotemporal patterns of China's digital economy efficiency

&lt;abstract&gt; &lt;p&gt;The digital economy has deeply integrated into various sectors, becoming a significant driving force for economic transformation and development, as new generation information technology continues to advance and mature. This paper builds upon theoretical analysis and employs the global Data Envelopment Analysis (DEA) method, along with relevant data from China's information transmission, software and information services industry spanning the years 2003 to 2020, to dynamically measure the output efficiency of China's digital economy. Based on this, the paper examines the overall characteristics of efficiency changes in the digital economy using distribution dynamics. Additionally, common descriptive statistics and data mapping techniques are utilized to reveal the spatiotemporal patterns of efficiency changes. The findings of the study are as follows: (1) The efficiency of the digital economy in the 31 provincial regions of China remains stable, but the factors influencing this efficiency vary both over time and among specific provinces. (2) From a temporal perspective, the digital economy in China demonstrates an overall positive increase in efficiency, with its volatility and differentiation largely shaped by the shifting factors of technological advancements and technological efficiency. (3) From a spatial perspective, there exists a distinct pattern of spatial disparities in China's digital economy efficiency, with higher efficiency observed in the eastern regions and lower efficiency in the western regions.&lt;/p&gt; &lt;/abstract&gt;

Initial Statistical Analysis Of Regional Development: Case Study Uzbekistan

The article presents the state and changes in the pattern of regional disparities in Uzbekistan over the years 2010-2018. In these studies, attention is paid to convergence in the socio-economic development of regions and in the analysis of their change, economic aspects come to the fore. The evolution of regional disparities is studied using convergence methods; σ-convergence and β-convergence. The convergence in the level of economic development of regions is examined in a dynamic approach based ongross regional product per capita. The results obtained using the σ- convergence methods are found to indicate decrease in regional differences in the years 2010-2016, a steady increase in 2016-2018. According to the results of β-convergence analysis, the differences in the development of the regions of Uzbekistan based ongross regional product per capita are slightly eliminated in the years 2010-2018.·

Learning a Compact Spatial-Angular Representation for Light Field

The recent emergence of light field technology has led to new opportunities for immersive visual communication that has a need for high spatial and angular resolution, both of which contribute to a large image storage footprint and high-latency transmission. Task-driven downsampling methods have been proposed as a solution, and have shown improvements in single-image restoration. However, they are inevitable to disregard light field's intrinsic properties in the corresponding tasks. In this paper, we propose a light-field-specific task-driven downsampling framework, called the LFCrNet. The LFCrNet operates on a learning-based decreasing and increasing resolution in an end-to-end manner in order to utilize a cross-view asymmetric sampling technique. In detail, it separates raw data into disparity and non-disparity patterns by measuring pixel-wise residuals between the sub-aperture central view and auxiliary views. Then, a chain of three-dimensional (3-D) deformable residual blocks (DRBs) is used to extract disparity features and manage these features regard of their intrinsic property individually. Afterwards, they are compacted into spatio-angular domains through a 3-D deformable downsampler (3-DDS). The non-disparity information is integrated into a separate pipeline that leverages spatial similarity across multiple light field views. This technique is capable of preserving specific occlusion components, and subsequently, restoring them using a learning-based upscaling method to generate a high-quality reconstruction. In general, our method has shown superior performance on multiple open-source datasets by a significant margin.