Beyond bulk: Density fractions explain heterogeneity in global soil carbon abundance and persistence.

Understanding the controls on the amount and persistence of soil organic carbon (C) is essential for predicting its sensitivity to global change. The response may depend on whether C is unprotected, isolated within aggregates, or protected from decomposition by mineral associations. Here, we present a global synthesis of the relative influence of environmental factors on soil organic C partitioning among pools, abundance in each pool (mg C g-1  soil), and persistence (as approximated by radiocarbon abundance) in relatively unprotected particulate and protected mineral-bound pools. We show that C within particulate and mineral-associated pools consistently differed from one another in degree of persistence and relationship to environmental factors. Soil depth was the best predictor of C abundance and persistence, though it accounted for more variance in persistence. Persistence of all C pools decreased with increasing mean annual temperature (MAT) throughout the soil profile, whereas persistence increased with increasing wetness index (MAP/PET) in subsurface soils (30-176 cm). The relationship of C abundance (mg C g-1  soil) to climate varied among pools and with depth. Mineral-associated C in surface soils (<30 cm) increased more strongly with increasing wetness index than the free particulate C, but both pools showed attenuated responses to the wetness index at depth. Overall, these relationships suggest a strong influence of climate on soil C properties, and a potential loss of soil C from protected pools in areas with decreasing wetness. Relative persistence and abundance of C pools varied significantly among land cover types and soil parent material lithologies. This variability in each pool's relationship to environmental factors suggests that not all soil organic C is equally vulnerable to global change. Therefore, projections of future soil organic C based on patterns and responses of bulk soil organic C may be misleading.

Comparison of methods for mapping rhizosphere processes in the context of their surrounding root and soil environments.

The rhizosphere embodies a complex biogeochemical zone with enhanced rates of nutrient exchange between plants, soil, and microbial communities. Understanding controls on rhizosphere dynamics is critical to support emerging concepts including rhizosphere engineering and reduced dependence on chemical fertilizers which have direct application to food production, increased biofuel generation, and habitat restoration efforts. Yet, its fine spatial scale and complex interactions between geochemical and microbial processes within complex spatiotemporal gradients make the rhizosphere notoriously difficult to study. Emerging instrumentation and methodologies, however, are providing improved resolution to rhizosphere measurements and helping to address critical knowledge gaps in rhizosphere function, ecology, and establishment. Here, we examine recent advances in analysis techniques and the resulting potential for improved understanding of rhizosphere function.

Development of a Web-Based Nonoperative Small Bowel Obstruction Treatment Pathway App.

OBJECTIVE: An electronic pathway for the management of adhesive small bowel obstruction (SBO) was built and implemented on top of the electronic health record. The aims of this study are to describe the development of the electronic pathway and to report early outcomes. METHODS: The electronic SBO pathway was designed and implemented at a single institution. All patients admitted to a surgical service with a diagnosis of adhesive SBO were enrolled. Outcomes were compared across three time periods: (1) patients not placed on either pathway from September 2013 through December 2014, (2) patients enrolled in the paper pathway from January 2017 through January 2018, and (3) patients enrolled in the electronic pathway from March through October 2018. The electronic SBO pathway pulls real-time data from the electronic health record to prepopulate the evidence-based algorithm. Outcomes measured included length of stay (LOS), time to surgery, readmission, surgery, and need for bowel resection. Comparative analyses were completed with Pearson's chi-squared, analysis of variance, and Kruskal-Wallis tests. RESULTS: There were 46 patients enrolled in the electronic pathway compared with 93 patients on the paper pathway, and 101 nonpathway patients. Median LOS was lower in both pathway cohorts compared with those not on either pathway (3 days [range 1-11] vs. 3 days [range 1-27] vs. 4 days [range 1-13], p = 0.04). Rates of readmission, surgery, time to surgery, and bowel resection were not significantly different across the three groups. CONCLUSION: It is feasible to implement and utilize an electronic, evidence-based clinical pathway for adhesive SBOs. Use of the electronic and paper pathways was associated with decreased hospital LOS for patients with adhesive SBOs.

COVID-19 infections among HCWs exposed to a patient with a delayed diagnosis of COVID-19.

We report on COVID-19 risk among HCWs exposed to a patient diagnosed with COVID-19 on day 13 of hospitalization. There were 44 HCWs exposed to the patient before contact and droplet precautions were implemented: of these, 2 of 44 (5%) developed COVID-19 potentially attributable to the exposure.