Ancient Lowland Maya neighborhoods: Average Nearest Neighbor analysis and kernel density models, environments, and urban scale.

Many humans live in large, complex political centers, composed of multi-scalar communities including neighborhoods and districts. Both today and in the past, neighborhoods form a fundamental part of cities and are defined by their spatial, architectural, and material elements. Neighborhoods existed in ancient centers of various scales, and multiple methods have been employed to identify ancient neighborhoods in archaeological contexts. However, the use of different methods for neighborhood identification within the same spatiotemporal setting results in challenges for comparisons within and between ancient societies. Here, we focus on using a single method-combining Average Nearest Neighbor (ANN) and Kernel Density (KD) analyses of household groups-to identify potential neighborhoods based on clusters of households at 23 ancient centers across the Maya Lowlands. While a one-size-fits all model does not work for neighborhood identification everywhere, the ANN/KD method provides quantifiable data on the clustering of ancient households, which can be linked to environmental zones and urban scale. We found that centers in river valleys exhibited greater household clustering compared to centers in upland and escarpment environments. Settlement patterns on flat plains were more dispersed, with little discrete spatial clustering of households. Furthermore, we categorized the ancient Maya centers into discrete urban scales, finding that larger centers had greater variation in household spacing compared to medium-sized and smaller centers. Many larger political centers possess heterogeneity in household clustering between their civic-ceremonial cores, immediate hinterlands, and far peripheries. Smaller centers exhibit greater household clustering compared to larger ones. This paper quantitatively assesses household clustering among nearly two dozen centers across the Maya Lowlands, linking environment and urban scale to settlement patterns. The findings are applicable to ancient societies and modern cities alike; understanding how humans form multi-scalar social groupings, such as neighborhoods, is fundamental to human experience and social organization.

Correlation of dental maturity with skeletal maturity from radiographic assessment: a review.

There have been many attempts to correlate dental development with skeletal growth. The relationship is generally considered to be moderate at best. However, there is evidence that hand-wrist radiographic interpretation of remaining growth can be augmented by taking into account the developing dentition. In addition, the practicality of evaluating routine dental radiographs and avoiding additional radiation is advantageous. To this point, no system has been described to match apical development by Demirjian's stages and compare it to skeletal development and remaining growth. This study reviewed articles pertinent to the relationship between developing teeth and skeletal maturity and remaining growth, and a system is proposed to give practitioners an additional assessment for growth and development.

Blood glucose variability is associated with mortality in the surgical intensive care unit.

Intensive insulin therapy has widely and rapidly been adopted as the standard of care for the treatment of hyperglycemia in the intensive care unit (ICU). Variability in blood glucose is increasingly recognized as an important factor in outcomes in the chronic diabetic in addition to hemoglobin A1C. We tested the hypothesis that measures of blood glucose variability would be associated with mortality in the surgical ICU. A retrospective analysis of a cohort of ventilated, critically ill surgical and trauma ICU patients placed on an automated insulin protocol was performed. Blood glucose (BG) variability was measured by comparing standard deviation, percentile values, successive changes in blood glucose, and by calculating the triangular index for various glucose-related indices. Eight hundred and fifty-eight patients had 46,474 blood glucose and insulin dose data points. One hundred and twenty-one patients died for an overall mortality rate of 14 per cent. Several measures of blood glucose variability (maximum successive change in BG and the triangular index) were different between the groups despite similar mean BG between survivors (117 mg/dL) and nonsurvivors (118 mg/dL). Increased blood glucose variability is associated with mortality in the surgical ICU. Further studies should focus on the demographic, clinical, and genetic factors responsible for this observation and identify strategies to minimize BG variability.