Spatiotemporal Changes in the Slavery-Inequality Relationship: The Diffusion of the Legacy of Slavery.

Despite the persistence of relationships between historical racist violence and contemporary Black-White inequality, research indicates, in broad strokes, that the slavery-inequality relationship in the United States has changed over time. Identifying the timing of such change across states can offer insights into the underlying processes that generate Black-White inequality. In this study, we use integrated nested Laplace approximation models to simultaneously account for spatial and temporal features of panel data for Southern counties during the period spanning 1900 to 2018, in combination with data on the concentration of enslaved people from the 1860 census. Results provide the first evidence on the timing of changes in the slavery-economic inequality relationship and how changes differ across states. We find a region-wide decline in the magnitude of the slavery-inequality relationship by 1930, with declines traversing the South in a northeasterly-to-southwesterly pattern over the study period. Different paces in declines in the relationship across states suggest the expansion of institutionalized racism first in places with the longest-standing overt systems of slavery. Results provide guidance for further identifying intervening mechanisms-most centrally, the maturity of racial hierarchies and the associated diffusion of racial oppression across institutions, and how they affect the legacy of slavery in the United States.

Population change and the legacy of slavery.

Despite increasing evidence of a contemporary legacy of slavery in the US South, scholars do not have a clear empirical understanding of the ways in which demographic forces can alter local connections to racial histories. In this study, we examine the influence of long-run trends in population change on the relationship between historical slave concentration and contemporary black-white poverty inequality in the American South. We combine one century and a half of county-level population data, including estimates of the slave and total populations in 1860, estimates of black and white population change starting in 1880, and black-white poverty disparities from the 2011-2015 American Community Survey. Our results offer new empirical evidence regarding the enduring influence of racial histories over time, and suggest that white population increase between 1880 and 1910 was particularly influential in understanding the local connection between slave concentration and black-white inequality. Moreover, rather than disrupting the transmission of the legacy of slavery, results indicate that white population increase may have helped spread this legacy of racial inequality to other counties through diffusion processes. We find that while local historical legacies are persistent, they are not permanent, and population trends are a critical force shaping local racial inequality.

Radiation Exposure Optimisation During AF Ablations Utilising the Cryoballoon Ablation System.

BACKGROUND: Radiation risk minimisation during cardiac catheterisation, particularly atrial fibrillation (AF) ablation procedures, requires a multifaceted approach involving both technique and technology. OBJECTIVE: To evaluate radiation dose associated with cryoballoon compared to conventional radiofrequency (RF) AF ablation procedures. METHODS: Consecutive patients undergoing AF ablation were collected in a single-centre registry. Radiation and procedural data for index AF ablation procedures using four ablation techniques were compared: RF ablation with and without the anti-scatter grid (RF Grid and RF Gridless), and cryoballoon ablation utilising first and second-generation Medtronic Arctic Front Cryoballoons (Cryo; Arctic Front, Medtronic, Minneapolis, MN, USA), with and without 3D imaging during fluoroscopy (Cryo 3D and Cryo). RESULTS: We studied 418 patients; 30 RF Grid, 68 RF No Grid, 12 Cryo 3D and 308 Cryo. The dose area product (DAP; Gycm2), adjusted for patient standardised weight of 80kg, was significantly higher for the Cryo 3D (21.91) and RF Grid (7.31) than the Cryo (2.13) and RF Gridless (3.31) groups; as a result, Cryo 3D was discontinued and RF Grid was only used when clinically required. Comparing the remaining groups, DAP for Cryo was significantly lower than RF Gridless (p<0.001) mainly attributable to a difference in fluoroscopy use (13.2 vs. 17.3 mins; p<0.001). Cryo procedure time was also significantly shorter (80 mins vs. 133 mins; p<0.01). CONCLUSION: Cryoballoon AF ablations can be performed efficiently using Gridless fluoroscopy techniques achieving significant reduction in radiation exposure and procedure time while maintaining safety and efficacy. In this observational study, cryoballoon AF ablations compare favourably to conventional RF ablations in terms of these parameters.

LINKING RACIAL COMPOSITION, BLACK-WHITE INEQUALITY, AND REGIONAL DIFFERENCE: THE ROLE OF MIGRATION.

The percent black-inequality relationship and the unique position of the South have been cornerstones of research on US racial inequality. Using an innovative methodological approach, I address how migration contributes to our understanding of the percent black-inequality relationship. I find that the educationally selective migration of blacks and whites significantly contributes to the percent black-inequality relationship via compositional changes. However, any explanatory power is limited to the non-South. Migration plays a role in understanding this relationship, yet processes related to black population concentration still generate black disadvantage anew, particularly within the South.

A Note on the Identification of Common Geographies.

Areal data have been used to good effect in a wide range of sociological research. One of the most persistent problems associated with this type of data, however, is the need to combine data sets with incongruous boundaries. To help address this problem, we introduce a new method for identifying common geographies. We show that identifying common geographies is equivalent to identifying components within a k-uniform k-partite hypergraph. This approach can be easily implemented using a geographic information system in conjunction with a simple search algorithm.

Multiracial identities, single race history: Contemporary consequences of historical race and marriage laws for racial classification.

This work interrogates the role of the law as an "actor" in the spatial patterning of racial classification. Laws governing racial intermarriage represent key ways that rigid distinctions between groups were codified. Critically, there is a great deal of state variation in these laws. We draw on a unique data set that combines samples from the 1990 and 2000 Census (5 percent IPUMS) and the 2009-2011 estimates from the American Community Survey with information on state-specific legal bans against intermarriage. Results from multilevel logistic and multinomial analyses indicate that a past of legal regulation is associated with a lower likelihood of a "mixed" classification for the offspring of black-white interracial unions, particularly in the 2009-11 period. Our results provide evidence that place-specific institutional legacies are imprinted on the classification choices made even in the midst of expanding options.

Outbreak of Mycobacterium chelonae infection associated with tattoo ink.

BACKGROUND: In January 2012, on the basis of an initial report from a dermatologist, we began to investigate an outbreak of tattoo-associated Mycobacterium chelonae skin and soft-tissue infections in Rochester, New York. The main goals were to identify the extent, cause, and form of transmission of the outbreak and to prevent further cases of infection. METHODS: We analyzed data from structured interviews with the patients, histopathological testing of skin-biopsy specimens, acid-fast bacilli smears, and microbial cultures and antimicrobial susceptibility testing. We also performed DNA sequencing, pulsed-field gel electrophoresis (PFGE), cultures of the ink and ingredients used in the preparation and packaging of the ink, assessment of source water and faucets at tattoo parlors, and investigation of the ink manufacturer. RESULTS: Between October and December 2011, a persistent, raised, erythematous rash in the tattoo area developed in 19 persons (13 men and 6 women) within 3 weeks after they received a tattoo from a single artist who used premixed gray ink; the highest occurrence of tattooing and rash onset was in November (accounting for 15 and 12 patients, respectively). The average age of the patients was 35 years (range, 18 to 48). Skin-biopsy specimens, obtained from 17 patients, showed abnormalities in all 17, with M. chelonae isolated from 14 and confirmed by means of DNA sequencing. PFGE analysis showed indistinguishable patterns in 11 clinical isolates and one of three unopened bottles of premixed ink. Eighteen of the 19 patients were treated with appropriate antibiotics, and their condition improved. CONCLUSIONS: The premixed ink was the common source of infection in this outbreak. These findings led to a recall by the manufacturer.

A biofilm model developed to investigate survival and disinfection of Mycobacterium mucogenicum in potable water.

Water in healthcare environments can be a source for healthcare-associated infections (HAI). However, information on the exposure risk to opportunistic pathogens in potable water distribution systems (PWDS) is lacking. Laboratory studies characterizing the interaction of opportunistic pathogens with biofilms are needed to understand their role in water systems within healthcare facilities. A stable, repeatable, PWDS multi-species biofilm model comprising Sphingomonas paucimobilis, Methylobacterium sp., Delftia acidovorans, and Mycobacterium mucogenicum was developed in the CDC Biofilm Reactor (CBR), reaching 6 log(10) CFU cm(-2) within 6 days. The model was used to investigate the interaction of the opportunistic pathogen M. mucogenicum with the other species, and to determine the efficacy of monochloramine (NH(2)Cl) as a disinfectant against 2-week-old biofilms. Addition of 1 or 2 mg l(-1) NH(2)Cl resulted in the same or an increased log density of viable M. mucogenicum in the biofilm while inactivating some of the Proteobacteria. Although M. mucogenicum preferentially resided in the biofilm, NH(2)Cl exposure caused release of viable M. mucogenicum from the biofilm into the water. Additional studies with this model should determine if sodium hypochlorite has a comparative effect and if other nontuberculous mycobacteria (NTM) respond to NH(2)Cl similarly.

National validation study of a cellulose sponge wipe-processing method for use after sampling Bacillus anthracis spores from surfaces.

This work was initiated to address the gaps identified by Congress regarding validated biothreat environmental sampling and processing methods. Nine Laboratory Response Network-affiliated laboratories participated in a validation study of a cellulose sponge wipe-processing protocol for the recovery, detection, and quantification of viable Bacillus anthracis Sterne spores from steel surfaces. Steel coupons (645.16 cm(2)) were inoculated with 1 to 4 log(10) spores and then sampled with cellulose sponges (Sponge-Stick; 3M, St. Paul, MN). Surrogate dust and background organisms were added to the sponges to mimic environmental conditions. Labs processed the sponges according to the provided protocol. Sensitivity, specificity, and mean percent recovery (%R), between-lab variability, within-lab variability, and total percent coefficient of variation were calculated. The mean %R (standard error) of spores from the surface was 32.4 (4.4), 24.4 (2.8), and 30.1 (2.3) for the 1-, 2-, and 4-log(10) inoculum levels, respectively. Sensitivities for colony counts were 84.1%, 100%, and 100% for the 1-, 2-, and 4-log(10) inocula, respectively. These data help to characterize the variability of the processing method and thereby enhance confidence in the interpretation of the results of environmental sampling conducted during a B. anthracis contamination investigation.

Achieving contrast-free ultra-low radiation exposure without compromising safety and acute efficacy through evolving AF cryoballoon ablation procedure techniques.

INTRODUCTION: In general, early experience with the first-generation cryoballoon introduced an increase in radiation exposure as compared to traditional radiofrequency ablations for atrial fibrillation (AF). However, through operator vigilance and the incorporation of various techniques and technologies, procedural radiation exposure can be managed to an exceptionally low level while maintaining the safety and efficacy of the cryoballoon procedure. METHODS AND RESULTS: A retrospective chart review of all consecutive AF ablation procedures performed by a single operator at a single high-volume center with the second-generation cryoballoon (Arctic Front Advance) was performed between 2014 and 2017. Procedural and radiation exposure data were collected and analyzed year-over-year. 307 cases were reviewed with the majority as index procedures (95%) and patients presenting in paroxysmal AF (87%). The observed median absorbed dose was 2.4 mGy (interquartile range (IQR) = 1.0,6.2) and decreased significantly from 6.7 mGy (IQR = 1.6,6.2) in 2014 to 2.0 mGy (IQR = 1.5,4.5) in 2017 (P < 0.001). Median fluoroscopy time was 0.4 min (IQR = 0.25,0.75) and demonstrated reductions from 0.75 min (IQR = 0.40,1.4) in 2014 to 0.20 min (IQR = 0.10,0.40) in 2017 (P < 0.001). No radiopaque contrast agent was used in any procedure. A complication rate of 2% (6 total events) was observed, and no cases resulted in stroke, death, permanent phrenic nerve injury, or pulmonary vein stenosis. In total, 304 of 307 (99%) procedures resulted in complete isolation of all pulmonary veins. CONCLUSION: Ultra-low radiation doses and contrast-free procedures can be achieved as part of an overall "safety-first" approach during cryoballoon AF ablation without compromising safety or acute efficacy.

Variability of Burkholderia pseudomallei strain sensitivities to chlorine disinfection.

Burkholderia pseudomallei is a select agent and the causative agent of melioidosis. Variations in previously reported chlorine and monochloramine concentration time (Ct) values for disinfection of this organism make decisions regarding the appropriate levels of chlorine in water treatment systems difficult. This study identified the variation in Ct values for 2-, 3-, and 4-log(10) reductions of eight environmental and clinical isolates of B. pseudomallei in phosphate-buffered water. The greatest calculated Ct values for a 4-log(10) inactivation were 7.8 mg.min/liter for free available chlorine (FAC) at pH 8 and 5 degrees C and 550 mg.min/liter for monochloramine at pH 8 and 5 degrees C. Ionic strength of test solutions, culture hold times in water, and cell washing were ruled out as sources of the differences in prior observations. Tolerance to FAC was correlated with the relative amount of extracellular material produced by each isolate. Solid-phase cytometry analysis using an esterase-cleaved fluorochrome assay detected a 2-log(10)-higher level of organisms based upon metabolic activity than did culture, which in some cases increased Ct values by fivefold. Despite strain-to-strain variations in Ct values of 17-fold for FAC and 2.5-fold for monochloramine, standard FAC disinfection practices utilized in the United States should disinfect planktonic populations of these B. pseudomallei strains by 4 orders of magnitude in less than 10 min at the tested temperatures and pH levels.

Parameters associated with acute morphometric lesion dimensions created by cryocatheters.

PURPOSE: Despite the wide use of cryoenergy, there is a paucity of data regarding the impact of certain ablation parameters on lesion size. Specifically, this study sought to evaluate the impact of catheter type, ablation time, heat load, and tip orientation on lesion dimensions using a porcine thigh model with focal cryoablation catheters. METHODS: In 6 pigs, 251 lesions were created on thigh muscle with parameter permutations to compare the acute impact of catheter type (electrode tip sizes 4, 6, and 8 mm), ablation time (2, 2 × 2, 3, 4, and 2 × 4 min), heat load (1 and 2 L/min), and tip orientation (perpendicular or parallel) on lesion dimensions (length, depth, and cross-sectional area) immediately post-ablation. As a sub-study to evaluate the importance of tissue contact during the cryoablation procedure, a 1-min freeze was performed without tissue contact until an ice ball formed, followed by an additional 2-3 min freeze. RESULTS: The linear regression model revealed that catheter type (p < 0.0001) and the interaction between catheter orientation and catheter type (p = 0.027) were significantly associated with lesion cross-sectional area. Lesion length and depth, but not cross-sectional area, are significantly impacted by the catheter type (p < 0.0001; p = 0.003) and orientation (p < 0.0001; p < 0.0001), respectively. Compared to parallel catheter placement, lesions created with the perpendicular orientation were deeper using 4-mm (p = 0.136), 6-mm (p = 0.005), and 8-mm tip catheter (p = 0.004). Lesion creation with an ice ball significantly reduced lesion depth compared to lesions made without an ice ball (p < 0.05). In contrast, ablation time (p = 0.097) and heat load (p = 0.467) were not significantly associated with lesion size. Additionally, there was no statistical significant difference in lesion size between 2 × 2 and 4 min ablation times. CONCLUSIONS: The present study demonstrated that lesion size was significantly impacted by catheter type and catheter tip orientation and that maintaining tissue contact prior to applying cryoenergy is essential.

The Spatial Distribution of Poverty and the Long Reach of the Industrial Makeup of Places: New Evidence on Spatial and Temporal Regimes.

A wealth of research identifies industrial structure as a central correlate of place-level poverty and suggests that changes in and the clustering of industry contribute to the spatial clustering of poverty over time. However, few studies have investigated the spatial and temporal dimensions simultaneously, and none have effectively examined spatio-temporal interactions. Consequently, a core tenet of theory on poverty in place has not been adequately examined. To address this limitation, we explicitly test hypotheses about systematic variation in the poverty-industry relationship over time and across space using a new method to quantify dynamic associations by simultaneously accounting for spatial and temporal autocorrelation and relationship heterogeneity. The Upper Midwest is our study site given dramatic regional changes in dominant industries (i.e., manufacturing, services, and agriculture) and poverty during the past several decades. We find that the specific character of the poverty-industry relationship systematically varies along both the temporal and spatial dimensions: industry is more protective in certain periods than in others according to sector trends, and is more protective in certain places than others conditional on sector dependence. Our approach yields a more precise and reliable understanding of the long reach of local industrial structure on the spatial clustering of poverty.

Multi-resolution border segmentation for measuring spatial heterogeneity of mixed population biofilm bacteria.

Multi-resolution image clustering and segmentation interactive system has been developed to analyze the interaction between clusters of heterogeneous microbial populations residing in biofilms. Biofilms are biological microorganisms attached to surfaces, which develop a complex heterogeneous three-dimensional structure. The hierarchical structural analysis concept underlying multi-resolution image segmentation is that the clusters will be more complex and noisy for higher-resolution while less complex and smoother for lower-resolution image. This hierarchical structure analysis can be used to simplify the image storage and retrieval in well-mixed populations. We are proposing an algorithm that combines Fuzzy C-Means, SOM and LVQ neural networks to segment and identify clusters. The outcome of the image segmentation is quantified by the number of cluster objects of each kind of microorganism within sections of the biofilm, and the centroid distances between the identified cluster objects. Experimental evaluations of the algorithm showed its effectiveness in enumerating cluster objects of bacteria in dual-species biofilms at the substratum and measuring the associated intercellular distances.

Clinic access and teenage birth rates: Racial/ethnic and spatial disparities in Houston, TX.

Teenage motherhood is a pressing issue in the United States, and one that is disproportionately affecting racial/ethnic minorities. In this research, we examine the relationship between the distance to the nearest reproductive health clinic and teenage birth rates across all zip codes in Houston, Texas. Our primary data come from the Texas Department of State Health Services. We use spatial regression analysis techniques to examine the link between clinic proximity and local teenage birth rates for all females aged 15 to 19, and separately by maternal race/ethnicity. We find, overall, limited support for a connection between clinic distance and local teenage birth rates. However, clinics seem to matter most for explaining non-Hispanic white teenage birth rates, particularly in high-poverty zip codes. The racial/ethnic and economic variation in the importance of clinic distance suggests tailoring clinic outreach to more effectively serve a wider range of teenage populations. We argue social accessibility should be considered in addition to geographic accessibility in order for clinics to help prevent teenage pregnancy.

Thirty-Second Gold Standard Definition of Atrial Fibrillation and Its Relationship With Subsequent Arrhythmia Patterns: Analysis of a Large Prospective Device Database.

BACKGROUND: The Heart Rhythm Society consensus statement arbitrarily defines atrial fibrillation (AF) ablation failure as any episode ≥30 seconds. However, if brief AF events are not correlated to longer events, the rationale for this end point is questionable. We determined the impact of AF episode duration threshold on AF incidence and burden. METHODS: Patients with a pacemaker in a prospective registry with device-detected AF and follow-up >30 days were analyzed. AF patterns were calculated for various AF duration thresholds (30 s; 2 and 6 minutes; 3.8, 5.5, and 24 hours) selected based on published consensus statements, established evidence of stroke risk, and device capabilities. Freedom from AF postdevice implant at each AF episode duration threshold was assessed, as was overall AF burden. RESULTS: Among 615 patients with pacemaker (aged 72.0±11.8 years, 54.2% male, follow-up 3.7±2.2 years) with device-detected AF, 599 had ≥1 AF episode of ≥30 seconds duration (median, 22 episodes). At 12 months, freedom from AF was 25.5%, 30.1%, 34.6%, 52.6%, 56.5%, and 73.1% for duration thresholds of 30 seconds, 2 minutes, 6 minutes, 3.8 hours, 5.5 hours, and 24 hours, respectively. Of patients with a first episode of 30 seconds to 2 minutes, 35.8% were free from subsequent episode >2 minutes at 180 days. Median AF burden was significantly less for patients with first episodes between 30 seconds and 3.8 hours versus >3.8 hours (0.2% versus 9.5%, respectively; P<0.0001). CONCLUSIONS: Small differences in AF episode duration definition can significantly affect the perceived incidence of AF and impact reported outcomes, including AF ablation success. An initial AF episode of 30 seconds does not predict clinically meaningful AF patterns.

HISTORICAL RACIAL CONTEXTS AND CONTEMPORARY SPATIAL DIFFERENCES IN RACIAL INEQUALITY.

Research examining regional variation in the impact of racial concentration on black-white economic inequality assumes that the American South is distinct from the non-South because of its slavery history. However, slavery's influence on the relationship has not been directly examined nor has it been adequately theorized within the economic inequality literature. We assess whether the link between contemporary black concentration and poverty disparities is structured by historical racial context. We find that while there is contemporary racial inequality throughout the United States, inequality-generating processes vary spatially and in ways that are tied to the local historical racial context.

Where there's smoke: Cigarette use, social acceptability, and spatial approaches to multilevel modeling.

I contribute to understandings of how context is related to individual outcomes by assessing the added value of combining multilevel and spatial modeling techniques. This methodological approach leads to substantive contributions to the smoking literature, including improved clarity on the central contextual factors and the examination of one manifestation of the social acceptability hypothesis. For this analysis I use restricted-use natality data from the Vital Statistics, and county-level data from the 2005-9 ACS. Critically, the results suggest that spatial considerations are still relevant in a multilevel framework. In addition, I argue that spatial processes help explain the relationships linking racial/ethnic minority concentration to lower overall odds of smoking.

Mucormycosis outbreak associated with hospital linens.

BACKGROUND: Mucormycosis is an invasive fungal infection with a high fatality rate. We investigated an outbreak of mucormycosis in a pediatric hospital to determine routes of pathogen transmission from the environment and prevent additional infections. METHODS: A case was defined as a hospital-onset illness consistent with mucormycosis, confirmed by culture or histopathology. Case-patient medical records were reviewed for clinical course and exposure to items and locations within the hospital. Environmental samples were collected from air and surfaces. Fungal isolates collected from case-patients and the environmental samples were identified using DNA sequencing. RESULTS: Five case-patients had hospital-associated cutaneous mucormycosis over an 11-month period; all subsequently died. Three case-patients had conditions known to be associated with susceptibility to mucormycosis, while 2 had cardiac conditions with persistent acidosis. The cases occurred on several different wards throughout the hospital, and hospital linens were the only exposure identified as common to the case-patients. Rhizopus species were recovered from 26 (42%) of 62 environmental samples from clean linens and associated areas and from 1 (4%) of 25 samples from nonlinen-related items. Case-patients were infected with Rhizopus delemar, which was also isolated from cultures of clean linens and clean linen delivery bins from the off-site laundry facility. CONCLUSIONS: Hospital linens were identified as a vehicle that carried R. delemar into contact with susceptible patients. Fungal species identification using DNA-based methods is useful for corroborating epidemiologic links in hospital outbreak investigations. Hospital linens should be laundered, packaged, shipped and stored in a manner that minimizes exposure to environmental contaminants.

Storage Effects on Sample Integrity of Environmental Surface Sampling Specimens with Bacillus anthracis Spores.

The effect of packaging, shipping temperatures and storage times on recovery of Bacillus anthracis. Sterne spores from swabs was investigated. Macrofoam swabs were pre-moistened, inoculated with Bacillus anthracis spores, and packaged in primary containment or secondary containment before storage at -15°C, 5°C, 21°C, or 35°C for 0-7 days. Swabs were processed according to validated Centers for Disease Control/Laboratory Response Network culture protocols, and the percent recovery relative to a reference sample (T0) was determined for each variable. No differences were observed in recovery between swabs held at -15° and 5°C, (p ≥ 0.23). These two temperatures provided significantly better recovery than swabs held at 21°C or 35°C (all 7 days pooled, p ≤ 0.04). The percent recovery at 5°C was not significantly different if processed on days 1, 2 or 4, but was significantly lower on day 7 (day 2 vs. 7, 5°C, 102, p=0.03). Secondary containment provided significantly better percent recovery than primary containment, regardless of storage time (5°C data, p ≤ 0.008). The integrity of environmental swab samples containing Bacillus anthracis spores shipped in secondary containment was maintained when stored at -15°C or 5°C and processed within 4 days to yield the optimum percent recovery of spores.