Shelby County Research Articles

Racial Metaphors

Racial Metaphors Nikhil Pal Singh (bio) Barack Obama sought the middle of the road. "It is incontrovertible that race relations have improved significantly in my lifetime," he told an interviewer in 2015. But, he added, "the legacy of slavery, Jim Crow, discrimination in almost every institution in our lives … that's still part of our DNA that's passed on." Nikole Hannah-Jones is not so optimistic. "Anti-black racism runs in the very DNA of this country," she wrote in the lead essay for the 1619 Project. The bequest of slavery, conjoined at the founding with America's vaunted claims to freedom and self-government, yielded a racial inheritance that we have not yet, and maybe never will, overcome. Saying "racism is in our DNA" is to speak metaphorically. The argument is not that racism is literally programmed in the genes. At the same time, the reference is curious, given the long, invidious association of genetics with the idea of "race" as embodied differences in moral character and cognitive ability. It is arguable that every instance of modern racism depends upon and returns to this intellectual source code. One might ask, then, why would anti-racists go there? To answer this question, we need a better account of the racial policy regimes and conflicts of the post–civil rights era. By the 1990s, three competing approaches with different conceptual vocabularies and legal arguments had emerged: one embraced the language of colorblindness, another emphasized the persistence of explicit racial bias, and a third focused on both more subtle and expansive notions of institutional or systemic racism. Until quite recently, colorblindness had won the law and policy argument. A curious metaphor in its own right, colorblindness suggests that the best way to address the stubborn and unpleasant fact of racial difference is by not seeing it with our full-spectrum capacities, if at all. Such a tortured conception belies an aggressive political project, inverting applications of equal protection under the Fourteenth Amendment to restrict antidiscrimination law, limit affirmative action and proactive school [End Page 103] desegregation, and provide race-neutral justifications for mass incarceration and voting rights restrictions. In the Obama years, whatever political truce had been forged among U.S. elites over colorblindness unraveled, particularly once states moved to limit voting after the Supreme Court's 2013 Shelby County v. Holder released them from federal oversight under the Voting Rights Act. Meanwhile, the persistent problem of racial disparities in police violence and criminal punishment erupted with a new intensity. The rise of Black Lives Matter protests gave decisive impetus to longstanding criticisms of the colorblind legal and policy regime, reinforcing the perception of racial stalemate during the post–civil rights era, with America's penal complex, according to a popular title, described as tantamount to a "new Jim Crow." The resurgent idea that "racism is in our DNA" has emerged as a shorthand for thinking about the historical continuities of racial domination and overturning the colorblind legal and policy approach. If colorblindness rests on the claim that the civil rights movement changed everything, the idea that racism is in our DNA borders on a fatalistic proposition that it changed little or nothing. Colorblindness counseled "benign neglect" in the face of persistent racial disparity, viewing the latter as a "tangle of pathology," which Daniel Patrick Moynihan famously argued was now "capable of perpetuating itself without assistance from the white world." The claim that "racism is in our DNA" insists instead that racial disparities are evidence of social injustice produced by racism, demanding policy remediation. The metaphors we live by tell us a lot about our predicament. Colorblindness—an impairment of the senses—was always more about sanctioned indifference to racial inequality than ensuring fairness. To explain away enduring racial disparities, colorblind partisans reopened the door to racist science and culturalist explanations of poverty. But those who focus exclusively on racial disparity risk falling into a trap of their own by treating racial differentiation as if it stands outside of history and determines its course. The bitter irony is that essentialist thinking about racial inheritance has crept back into contemporary life, as we can see in the turn to epigenetic trauma, DNA...

The St. Jude STEM Clubs: An Afterschool STEM Club for Upper Elementary School Students in Memphis, TN.

Informal science, technology, engineering, and math (STEM) programs are important tools for broadening participation in STEM careers. The St. Jude STEM Club (SJSC) is a 10-week afterschool STEM club focused on real-world problems in pediatric cancer research and designed for students in the fifth grade. The SJSC is conducted in partnership with the Shelby County Schools (SCS), an urban school district that encompasses Memphis, TN and serves a disproportionate number of students from underrepresented backgrounds in science. In this report, we provide details on the club logistics, curriculum, pilot data and outcomes related to club impact on student attitudes towards science, and challenges and limitations of the program. Participants in the program reported significantly higher rates of STEM engagement, STEM identity, critical thinking, perseverance, and relationships with peers and adults compared to national normative data. This program description is intended to serve as a resource for other institutions wanting to use a similar strategy to broaden participation in STEM careers.

Impact of Single-Family Home Foreclosures on Apartment Rents

We examine the impacts of single-family home foreclosures on rents for 513 apartment buildings in Shelby County, Tennessee from 2001 through 2016. We find significant, positive nonlinear relationships between foreclosure rates and apartment rents, suggesting that foreclosure market shocks increase demand for apartments and cause occupancy changes from owner to renter. Specifically, rents increase with increasing nearby neighborhood single-family home foreclosure rates. Foreclosure effects were exacerbated by the higher acute foreclosure rates occurring during the 2007–2009 financial crisis, indicating greater price impacts on rents, while during periods with lower foreclosure rates, price impacts were more attenuated. Additionally, impacts on rents vary by rent levels with greater rent increases for higher-end apartments relative to lower-end units.

Residential greenspace and attention problems in early childhood

Background: Observational and experimental studies suggest that access to greenspace and spending time in parks both reduce symptoms of inattention and improve behavioral outcomes among children. Parks may provide an opportunity for intervention, yet few studies in the US have examined the potential benefits of access to public urban greenspace in early childhood. Methods: Within the ECHO-PATHWAYS Consortium, we investigated associations between residential proximity to publicly accessible parks and attention problems in the Conditions Affecting Neurocognitive Development and Learning in Early Childhood (CANDLE) study in Shelby County, TN. At child age 4-6, mothers completed the Child Behavior Checklist that assessed attention problems on a five-item scale. Park proximity was calculated as the Euclidean distance between the residential location at the time of this assessment and the edge of the nearest park. In Poisson regression models, we adjusted for child, maternal, and neighborhood characteristics. Results: In CANDLE, 65% of mothers identified as black, 29% white; 53% had at least a college or technical school degree. Children (N=886) were 4.3 (SD 0.4) years at the time of assessment; 51% were males; and 28% lived within 300m of a park. Preliminary results found no association between park proximity and child attention problems as a continuous measure (1% decrease in attention problems per two-fold increase in park proximity, 95%CI: -4%,4%) or dichotomized at a clinical threshold (risk ratio=1.02, 95%CI: 0.88,1.19). Effect modification by child sex was not statistically significant (pinteraction=0.12). Conclusions: While no significant associations were observed in the full sample or by child sex in this preliminary analysis, residential proximity is an imperfect proxy for access or exposure to greenspace. Future analyses will utilize greenspace exposures that additionally include private land and street trees, as well as investigating neighborhood factors, such as crime rate, that may affect children’s use of public greenspace.

Prenatal polycyclic aromatic hydrocarbon (PAH) exposure and early childhood asthma in a diverse US pregnancy cohort

Background/AimExposure to polycyclic aromatic hydrocarbons (PAH) may increase risk of pediatric asthma. Effects of prenatal PAH exposure, specifically, are hypothesized but understudied. The ECHO PATHWAYS Consortium investigated these relationships in a large, diverse prospective cohort study.MethodsWe included 919 mother-child dyads from the CANDLE Study, a longitudinal pregnancy cohort set in Shelby County, TN. PAH metabolites were measured in second trimester urine and adjusted for specific gravity. Seven metabolites detected in >80% of women were included in analysis. When children were 4-6 years old, mothers completed the International Study on Allergies and Asthma in Childhood survey. Poisson regression with robust standard errors was used to estimate relative risk of current wheeze, current asthma, and ever asthma associated with each metabolite in separate models, adjusted for maternal age, race, education and other asthma risk factors. Effect modification by child sex and maternal asthma was assessed using interaction models. We did not adjust for multiple comparisons.ResultsParticipants were 66% Black, 44% White; 58% with high school education or less. On average, urinary PAH metabolite concentrations were higher than in other US cohorts. Mean (SD) child age at assessment was 4.3 (0.4) years. Prevalence of reported current wheeze and asthma and ever asthma was 19.4%, 16.1%, and 14.6%, respectively. In multivariable models, we observed no evidence that any metabolite was associated with any outcome. No differences by child sex were observed. Maternal asthma modified associations between 1/9-hydroxyphenanthrene and current asthma (RRmaternal asthma = 0.88; 95%CI: 0.78, 0.99 versus RRwithout maternal asthma = 1.09; 95%CI: 0.97, 1.23 per two-fold increase in exposure; pinteraction=0.012).ConclusionsResults of our analysis, the largest cohort study of prenatal PAH and childhood airway outcomes conducted to date, did not support the hypothesis that prenatal PAHs increases risk of early childhood asthma.

Prenatal phthalate exposure is associated with changes to the placental transcriptome

Background: Phthalates disrupt processes involved in placental physiology and fetal development and are associated with a variety of adverse health outcomes in infants and children. The goal of this study was to identify associations between prenatal phthalate exposure and the placental transcriptome. Methods: Maternal urine was collected during the third trimester and placental tissue was collected at delivery from 404 women enrolled in the CANDLE study (Shelby County Tennessee, USA). Sample analyses were conducted by the ECHO PATHWAYS Consortium. 15 phthalate urinary metabolites were quantified using high-performance liquid chromatography-mass spectrometry. Placental transcriptomic data was generated using paired-end RNA sequencing. Linear models were fit using limma-voom to identify associations between each phthalate metabolite (independent variable) and each gene (dependent variable). We used models adjusted only for sequencing batch and models fully adjusted for confounders: maternal education; race and age; sequencing batch; fetal sex; and labor type. Genes were considered statistically significant at a Benjamini-Hochberg false discovery rate (FDR) <0.05. For pathway overrepresentation analysis, we included genes significantly associated with phthalates from minimally adjusted models at an FDR <0.15. Results: We identified 39 pathways associated with one or more of 5/15 phthalates. MMP MBZP, and MBP concentrations were associated with the highest number of genes and pathways. The RIG-1-like receptor signaling pathway, intestinal immune network for IgA production, and the complement and coagulation cascade pathways were enriched for genes associated with multiple phthalates. No genes were statistically significantly associated with urinary phthalate measurements in our fully adjusted model. Conclusion: In this first genome-wide assessment of the third-trimester placental transcriptome, we identified genes associated with phthalate exposure. These genes were related to xenobiotic metabolism, oxidative stress, PPAR signaling, and immune dysregulation, concurrent with phthalates known molecular mechanisms within the placenta. Ongoing work includes collecting additional data and identification of transcriptional regulators.

Maternal exposure to childhood traumatic events, but not multi-domain psychosocial stressors, predict placental corticotrophin releasing hormone across pregnancy.

Maternal psychosocial stress increases the risk of adverse birth and postnatal outcomes for the mother and child, but the role of maternal exposure to childhood traumatic events (CTE) and multi-domain psychosocial stressors for the level and rise of placental Corticotrophin-Releasing Hormone (pCRH) across pregnancy has been understudied. In a sociodemographically and racially diverse sample of 1303 women (64% Black, 36% White/others) with low-medical risk pregnancies at enrollment from Shelby County, Tennessee, USA, blood samples were drawn twice, corresponding roughly to second and third trimester, and extracted prior to conducting radioimmune assays for pCRH. Mothers reported CTE (physical abuse, sexual abuse, or family violence, in childhood), adulthood traumatic events, and interpersonal violence during pregnancy. Neighborhood crime/deprivation was derived using geospatially-linked objective databases. General linear and mixed models tested associations between stress exposure variables and pCRH levels and rate of rise, adjusting for obstetric/clinical/health related factors. Maternal CTE did not predict pCRH levels at time 1, but positively predicted levels at time 2, and the rate of rise in pCRH across pregnancy. Race did not moderate this association. No additional maternal stress exposures across adulthood or during pregnancy predicted pCRH outcomes. Findings indicate that childhood violence or abuse exposure can become biologically embedded in a manner predicting later prenatal physiology relevant for maternal and offspring health, and that such embedding may be specific to childhood, but not adulthood, stress. Findings also highlight the placental-fetal unit as a mechanistic pathway through which intergenerational transmission of the adverse effects of childhood adversities may occur.

An integrated social vulnerability assessment of riverine flood hazards in Shelby County, Tennessee

PurposeVulnerability studies are commonly used to inform planning, as cities and regions seek to build resilience to environmental hazards. In Shelby County, Tennessee, socioeconomic census tract data were mapped to identify the socially vulnerable population and places to underpin strategies in the Mid-South Regional Resilience Master Plan (RRMP). While this is an important step in identifying vulnerability in the county, this paper aims to enhance the local analysis through an integrated approach that considers both social factors and environmental hazards in assessing vulnerability.Design/methodology/approachThis paper conducts a social vulnerability assessment by integrating a social vulnerability index with risk exposure analysis at the census tract level to identify the population and places vulnerable to riverine flooding in Shelby County.FindingsThe analysis reveals that social vulnerability assessments that do not relate socioeconomic factors to specific environmental hazards such as riverine flooding underestimate the population and places that are vulnerable. For Shelby County, this has the tendency to undermine the prioritization and effectiveness of strategies to build resilience to riverine flooding and can worsen preexisting marginalization.Practical implicationsThis paper recommends integrated vulnerability assessments for each of the environmental hazards identified in the Mid-South RRMP to augment existing resilience efforts in the county.Originality/valueThis paper enhances the understanding of social vulnerability assessments by consolidating the need for integrated assessment frameworks as basis for resiliency planning.

Development of a COVID‐19 alternate care site from ground zero: A nursing perspective

The novel coronavirus disease SARS‐CoV‐2 (COVID‐19) outbreak rapidly generated an unprecedented global, national, and state public health crisis with the need to rapidly develop alternate care sites (ACS) to care for COVID‐19 patients within an overburdened health care system. A hospital care model ACS to increase the health care capacity, provide care for mild to moderately symptomatic patients, and offer local self‐sustainment for a surge of patients was developed in Memphis, Tennessee located in Shelby County. We completed a temporary conversion of a large unused newspaper publication building to a health care facility for COVID‐19 patients. Developing an ACS from ground zero was met with many challenges, and throughout the process important lessons were learned. With the goal to complete the building conversion within a 28‐day timeframe, collaboration among the numerous governmental, health care, and private agencies was critical and nursing leadership was key to this process. The purpose of this paper is to describe the development of a COVID‐19 ACS in Memphis, TN, which has a large at‐risk population with limited access to health care. Specifically, we will discuss the strong leadership role of nursing faculty, key challenges, and lessons learned, as well as provide checklists and models for others in similar circumstances.

Identification of Modifiable Social and Behavioral Factors Associated With Childhood Cognitive Performance

Inequities in social environments are likely associated with a large portion of racial disparities in childhood cognitive performance. Identification of the specific exposures associated with cognitive development is needed to inform prevention efforts. To identify modifiable factors associated with childhood cognitive performance. This longitudinal pregnancy cohort study included 1503 mother-child dyads who were enrolled in the University of Tennessee Health Science Center-Conditions Affecting Neurodevelopment and Learning in Early Life study between December 1, 2006, and July 31, 2011, and assessed annually until the children were aged 4 to 6 years. The analytic sample comprised 1055 mother-child dyads. A total of 155 prenatal, perinatal, and postnatal exposures were included to evaluate environment-wide associations. Participants comprised a community-based sample of pregnant women who were recruited between 16 weeks and 28 weeks of gestation from 4 hospitals in Shelby County, Tennessee. Women with high-risk pregnancies were excluded. Data were analyzed from June 1, 2018, to April 15, 2019. Individual and neighborhood socioeconomic position, family structure, maternal mental health, nutrition, delivery complications, birth outcomes, and parenting behaviors. Child's full-scale IQ measured by the Stanford-Binet Intelligence Scales, Fifth Edition, at age 4 to 6 years. Of 1055 children included in the analytic sample, 532 (50.4%) were female. Among mothers, the mean (SD) age was 26.0 (5.6) years; 676 mothers (64.1%) were Black, and 623 mothers (59.0%) had an educational level of high school or less. Twenty-four factors were retained in the least absolute shrinkage and selection operator regression analysis and full models adjusted for potential confounding. Associations were noted between child cognitive performance and parental education and breastfeeding; for each increase of 1.0 SD in exposure, positive associations were found with cognitive growth fostering from observed parent-child interactions (β = 1.12; 95% CI, 0.24-2.00) and maternal reading ability (β = 1.42; 95% CI, 0.16-2.68), and negative associations were found with parenting stress (β = -1.04; 95% CI, -1.86 to -0.21). A moderate increase in these beneficial exposures was associated with a notable improvement in estimated cognitive test scores using marginal means (0.5% of an SD). Black children experienced fewer beneficial cognitive performance exposures; in a model including all 24 exposures and covariates, no racial disparity was observed in cognitive performance (95% CIs for race included the null). The prospective analysis identified multiple beneficial and modifiable cognitive performance exposures that were associated with mean differences in cognitive performance by race. The findings from this observational study may help guide experimental studies focused on reducing racial disparities in childhood cognitive performance.

Regional resilience analysis: A multiscale approach to optimize the resilience of interdependent infrastructure

AbstractReducing hazard‐induced disruptions to infrastructure functionality is cardinal to regional resilience. Specifically, effective strategies to enhance regional resilience require: (a) developing mathematical models for infrastructure recovery; (b) quantifying resilience associated with the developed recovery process; and (c) developing a computationally manageable approach for resilience optimization. This paper proposes a rigorous mathematical formulation to model recovery, quantify resilience, and optimize the resilience of large‐scale infrastructure. Specifically, a multiscale model of the recovery process is proposed that significantly reduces the computational cost, while favoring practical and easily manageable recovery schedules. To quantify regional resilience, resilience metrics are proposed that capture the temporal and spatial variations of the recovery process. The paper then formulates a multiobjective optimization problem that aims to improve regional resilience in terms of the proposed metrics, while minimizing the recovery cost. Finally, the paper illustrates the proposed formulation by considering interdependent infrastructure in Shelby County, Tennessee, United States.

The Disenfranchisement of Voters of Color: Redux

This article unpacks how voters of color continue to be disenfranchised by policy and administrative action. In 2013, the US Supreme Court issued a decision in Shelby County v. Holder, which struck down key provisions of the Voting Rights Act of 1965. This ruling sets the stage for states to change their election laws which have perpetuated voter suppression and the disenfranchisement of people of color and low-income whites. The article examines the practices and policies across the states, with a focus on the role of public administrators. Current election policies in a number of states force administrators to confront the challenges of promoting values of efficiency and effectiveness with the normative values of equity and fairness. While public administrators have an obligation to be non-partisan, there must be a focus on access and equity that extends to the ballot box.

Tennessee Education Savings Account: Tipping the Scales From Equity to Choice

This article provides an analysis of Tennessee’s newly signed Education Savings Account policy, a school choice initiative. The policy provides vouchers, in the form of a debit card, to students in grades K-12 who are at or below 200% of the federal poverty line and are zoned to attend a Nashville, Shelby County, or Achievement School District school. Using the Policy Window Framework the author uncovers that the policy was created in a federal and state-level political convergence, which attempted to place equity at the forefront of the issue. However, using Levin's Comprehensive Education Privatization Framework, we can see that neoliberal ideals of choice and efficiency conquer equity in the finalized policy. The author predicts the outcomes of this new policy using this framework in tandem with 3 case studies: Louisiana Scholarship Program, DC Opportunity Scholarship Program, and Tennessee’s Individualized Education Accounts.

The Politics of Locating Polling Places: Race and Partisanship in North Carolina Election Administration, 2008–2016

Do local election administrators change precincts and Election Day polling place locations to target voters based on their partisanship or race? We systematically evaluate whether decisions consistent with targeting occur using the near universe of eligible voters, polling place locations, and precinct boundaries across three presidential elections in the closely contested state of North Carolina. We find no evidence that local administrators allocate precincts and polling places in a manner consistent with partisan manipulation for electoral gain. Some counties appear to differentially target opposition party voters with these changes, but the county-level variation we document is likely due to random variation rather than deliberate manipulation. There is also little evidence that the removal of minority voter protections in Shelby County v. Holder impacted polling place placement. If partisan-motivated precinct or polling place decisions occur in North Carolina, they are seemingly more idiosyncratic than pervasive.

Pattern‐based calibration of cellular automata by genetic algorithm and Shannon relative entropy

AbstractWhile cellular automata (CA) are considered an effective algorithm to model urban growth, their precise calibration can be challenging. The Shannon relative index (SRI) is an indicator of urban sprawl accounting for dispersion or concentration of built‐up/non‐built‐up areas. This study uses SRIs directly in the calibration of CA as patterns, applying a genetic algorithm (GA). Moreover, the kappa coefficient is used in the calibration process. CA was calibrated using data for 2001 and 2006 and validated using 2011 data to model urban growth in Shelby County, TN. Results indicate that the kappa coefficient achieves the highest value using the proposed method (89.48%) compared with a GA without patterns (86.15%, which underestimates 32.22 km2) or logistic regression (85.83%, which underestimates 36.76 km2). A more precise calibration of urban growth using the proposed method helps city planners to provide more realistic models for the future of the region.

Voter Purges After Shelby

In Shelby County v. Holder (570 U.S. 529 (2013)), the U.S. Supreme Court struck down the “coverage formula” in Section 4b of the Voting Rights Act (VRA) that determined which jurisdictions had to presubmit changes in their election policies for federal approval. This ruling allowed covered counties full control over their election laws for the first time in 40 years. We engage the question of whether counties that had previously been “covered” purged voters at a higher rate than noncovered counties after the coverage formula was struck down. We find increases in purge rate of between 1.5 and 4.5 points in formerly covered jurisdictions post- Shelby, compared with counties that had not been subject to preclearance. Most of the increase came immediately, as the effect in 2014 is substantively and significantly higher than that in 2016. These findings suggest that while counties may have aggressively purged voters in 2014—the first election after the coverage formula’s demise—they may have tempered this behavior thereafter.

Moving Forward or Backsliding: A Causal Inference Analysis of the Effects of theShelbyDecision in North Carolina

The Voting Rights Act created a method of oversight called “preclearance,” which was designed to prevent changes in state and local voting laws that may negatively affect minority groups. Following the ruling in Shelby County v. Holder, however, preclearance is no longer enforced. This study assesses the impact of recently implemented local voting restrictions on turnout across various demographic and political subgroups in North Carolina. Unlike other states, preclearance in North Carolina was implemented at the county level. Two approaches to the regression discontinuity-design are used to estimate de facto minority disenfranchisement. This study finds that the removal of Section 5 preclearance negatively affected Democratic primary turnout, but did not affect Democratic vote share. Secondary effects resulting in the removal of Section 5 preclearance may be responsible for disproportionately lower levels of overall turnout in formerly covered counties in 2016. Ultimately, the data suggest minimal effects on minority turnout rates.

School Personnel’s Knowledge, Attitudes, and Management Practices about Diabetes Care in Shelby County, TN, and Surrounding Counties in Arkansas and Mississippi

Background: Approximately 130,000 people under age 18 years have diabetes. It is estimated that type 1 diabetes is growing at 3% per year in children and adolescents. With more children with diabetes there has been a shift in care from trained professionals to unlicensed personnel. Children and adolescents with uncontrolled diabetes are at an increased risk of developing serious health problems and reduced life expectancy. Therefore, fragmented care within the school setting only exacerbates the risk of poor health outcomes of children and adolescents with diabetes.

A Republic, If the Courts Can Keep It?

This contribution to a conference celebrating Andrew Coan’s Rationing the Constitution: How Judicial Capacity Shapes Supreme Court Decision-Making (Harvard Univ. Press, 2019) makes three primary points. First, I explain why the Supreme Court’s flawed reasoning in INS v. Chadha supports Coan’s judicial capacity theory of Supreme Court decision making. Second, I show why judicial capacity concerns do not support the Supreme Court’s decision in Rucho v. Common Cause to treat the constitutionality of partisan gerrymandering as a nonjusticiable political question. The Court could and should have announced a bright line rule against any partisan calculation in districting decision making, and let lower courts adjudicate the pure question of fact that such a rule would raise. Recent scholarship is converging in this direction. The weakness in Justice Kagan’s dissent lay in conceding any place for partisan calculation in districting. Predominant purpose tests, pulled across from racial affirmative action cases, do not fit partisan gerrymandering. Even the Court’s staunchest opponents of racial affirmative action concede that the goals of that action may be laudable; those opponents just contend that weightier moral reasons call for race neutrality in almost all circumstances. No one on the Court uses “laudable” to describe the goals of partisan gerrymandering. Partisan reasons are not redeemed by being low impact. Partisan reasons should have no impact on governing actions. Third, I argue that the Court should have identified a nonjusticiable political question not in Rucho, but, as other recent scholarship has suggested, in Shelby County v. Holder. Congress’s provision for preclearance in the Voting Rights Act serves not only to uphold the promises of the fourteenth and fifteenth amendments, but also to fulfill the national government’s constitutional duty to guarantee every state in the Union a republican form of government. The Court has long held that it will not second guess the judgment of the elected branches about what republican form requires.

Modeling Uncertain and Dynamic Interdependencies of Infrastructure Systems Using Stochastic Block Models

Abstract Modeling the resilience of interdependent critical infrastructure (ICI) requires a careful assessment of interdependencies as these systems are becoming increasingly interconnected. The interdependent connections across ICIs are often subject to uncertainty due to the lack of relevant data. Yet, this uncertainty has not been properly characterized. This paper develops an approach to model the resilience of ICIs founded in probabilistic graphical models. The uncertainty of interdependency links between ICIs is modeled using stochastic block models (SBMs). Specifically, the approach estimates the probability of links between individual systems considered as blocks in the SBM. The proposed model employs several attributes as predictors. Two recovery strategies based on static and dynamic component importance ranking are developed and compared. The proposed approach is illustrated with a case study of the interdependent water and power networks in Shelby County, TN. Results show that the probability of interdependency links varies depending on the predictors considered in the estimation. Accounting for the uncertainty in interdependency links allows for a dynamic recovery process. A recovery strategy based on dynamically updated component importance ranking accelerates recovery, thereby improving the resilience of ICIs.