Extreme environments simplify reassembly of communities of arbuscular mycorrhizal fungi.

The ecological impacts of long-term (press) disturbance on mechanisms regulating the relative abundance (i.e., commonness or rarity) and temporal dynamics of species within a community remain largely unknown. This is particularly true for the functionally important arbuscular mycorrhizal (AM) fungi; obligate plant-root endosymbionts that colonize more than two-thirds of terrestrial plant species. Here, we use high-resolution amplicon sequencing to examine how AM fungal communities in a specific extreme ecosystem-mofettes or natural CO2 springs caused by geological CO2 exhalations-are affected by long-term stress. We found that in mofettes, specific and temporally stable communities form as a subset of the local metacommunity. These communities are less diverse and dominated by adapted, "stress tolerant" taxa. Those taxa are rare in control locations and more benign environments worldwide, but show a stable temporal pattern in the extreme sites, consistently dominating the communities in grassland mofettes. This pattern of lower diversity and high dominance of specific taxa has been confirmed as relatively stable over several sampling years and is independently observed across multiple geographic locations (mofettes in different countries). This study implies that the response of soil microbial community composition to long-term stress is relatively predictable, which can also reflect the community response to other anthropogenic stressors (e.g., heavy metal pollution or land use change). Moreover, as AM fungi are functionally differentiated, with different taxa providing different benefits to host plants, changes in community structure in response to long-term environmental change have the potential to impact terrestrial plant communities and their productivity.IMPORTANCEArbuscular mycorrhizal (AM) fungi form symbiotic relationships with more than two-thirds of plant species. In return for using plant carbon as their sole energy source, AM fungi improve plant mineral supply, water balance, and protection against pathogens. This work demonstrates the importance of long-term experiments to understand the effects of long-term environmental change and long-term disturbance on terrestrial ecosystems. We demonstrated a consistent response of the AM fungal community to a long-term stress, with lower diversity and a less variable AM fungal community over time under stress conditions compared to the surrounding controls. We have also identified, for the first time, a suite of AM fungal taxa that are consistently observed across broad geographic scales in stressed and anthropogenically heavily influenced ecosystems. This is critical because global environmental change in terrestrial ecosystems requires an integrative approach that considers both above- and below-ground changes and examines patterns over a longer geographic and temporal scale, rather than just single sampling events.

Implementation Research at NHLBI: Methodological and Design Challenges and Lessons Learned from the DECIPHeR Initiative.

NHLBI funded seven projects as part of the Disparities Elimination through Coordinated Interventions to Prevent and Control Heart and Lung Disease Risk (DECIPHeR) Initiative. They were expected to collaborate with community partners to (1) employ validated theoretical or conceptual implementation research frameworks, (2) include implementation research study designs, (3) include implementation measures as primary outcomes, and (4) inform our understanding of mediators and mechanisms of action of the implementation strategy. Several projects focused on late-stage implementation strategies that optimally and sustainably delivered two or more evidence-based multilevel interventions to reduce or eliminate cardiovascular and/or pulmonary health disparities and to improve population health in high-burden communities. Projects that were successful in the three-year planning phase transitioned to a 4-year execution phase. NHLBI formed a Technical Assistance Workgroup during the planning phase to help awardees refine study aims, strengthen research designs, detail analytic plans, and to use valid sample size methods. This paper highlights methodological and study design challenges encountered during this process. Important lessons learned included (1) the need for greater emphasis on implementation outcomes, (2) the need to clearly distinguish between intervention and implementation strategies in the protocol, (3) the need to address clustering due to randomization of groups or clusters, (4) the need to address the cross-classification that results when intervention agents work across multiple units of randomization in the same arm, (5) the need to accommodate time-varying intervention effects in stepped-wedge designs, and (6) the need for data-based estimates of the parameters required for sample size estimation.

An investigation of movement dynamics and muscle activity during traditional and accentuated-eccentric squatting.

INTRODUCTION: Accentuated-eccentric loading (AEL) takes advantage of the high force producing potential of eccentric muscle contractions, potentially maximising mechanical tension within the muscle. However, evidence is lacking on how AEL squatting may load the involved musculature, limiting scientifically justified programming recommendations. The purpose of this study was to investigate the effects of concentric and eccentric loads on joint loading and muscle activity of the lower limbs. METHODS: Resistance trained males performed traditional squatting (20-100% of concentric one-repetition maximum [1RM]) and AEL squatting with eccentric loads (110-150% of 1RM) provided by a novel motorised isotonic resistance machine (Kineo). Kinetics and kinematics of the hip, knee, and ankle joints were collected, with electromyography from the gluteus maximus, vastus lateralis, biceps femoris, and gastrocnemius medialis. A secondary cohort underwent a kinematic and electromyography analysis of squatting technique to compare Kineo and back and front barbell squatting. RESULTS: Knee joint peak eccentric moments occurred at 120% 1RM (P = 0.045), with no further increase thereafter. As eccentric load increased, the time course of moment development occurred earlier in the eccentric phase. This resulted in a 37% increase in eccentric knee extensor work from the 80% 1RM trial to the 120% 1RM trial (P<0.001). Neither hip nor ankle joints displayed further change in kinetics as eccentric load increased above 100% 1RM. Electromyographic activity during traditional squatting was ~15-30% lower in all eccentric trials than in concentric trials for all muscles. EMG plateaued between a load of 80-100% 1RM during the eccentric trials and did not increase with AEL. No significant differences in kinematics were found between Kineo and barbell squatting. CONCLUSIONS: The knee extensors appear to be preferentially loaded during AEL squatting. The greater work performed during the eccentric phase of the squat as eccentric load increased suggests greater total mechanical tension could be the cause of adaptations from AEL. Our data suggest that AEL should be programmed with a load of 120% of 1RM. Further studies are needed to confirm the longer-term training effects of AEL.

Hydrological properties predict the composition of microbial communities cycling methane and nitrogen in rivers.

Sediment microbial communities drive the biogeochemical cycles that make rivers globally important sources and sinks of carbon (C) and nitrogen (N). The structure of these communities is strongly determined by the local physico-chemical environment. However, we currently lack an understanding of the factors that determine microbial community structures at the catchment scale. Here, we show that the contribution of groundwater to total river flow (quantified as base flow index; BFI) predicts the structure and diversity of the different microbial functional groups that cycle N and C across nine UK rivers, spanning a geological BFI gradient from 0.23 (clay sediment) to 0.95 (chalk gravel sediment). Furthermore, the GC-content (percentage of guanine-cytosine bases in a DNA sequence) and codon-usage bias of ammonia monooxygenase DNA sequences, and the hydrophobicity and net-charge of the corresponding amino acid sequences, were all strongly correlated with BFI, likely reflecting physiological adaptations to different riverbed sediment structure along the BFI gradient. Our results offer an opportunity to overcome the "paradox of scales" that has seen microbial ecologists focus on small- rather than large-scale environmental variables, enabling us to scale-up our understanding of microbial biogeochemistry to the catchment and beyond.

Leveraging HIV Care Infrastructures for Integrated Chronic Disease and Pandemic Management in Sub-Saharan Africa.

In Sub-Saharan Africa, communicable and other tropical infectious diseases remain major challenges apart from the continuing HIV/AIDS epidemic. Recognition and prevalence of non-communicable diseases have risen throughout Africa, and the reimagining of healthcare delivery is needed to support communities coping with not only with HIV, tuberculosis, and COVID-19, but also cancer, cardiovascular disease, diabetes, and depression. Many non-communicable diseases can be prevented or treated with low-cost interventions, yet implementation of such care has been limited in the region. In this Perspective piece, we argue that deployment of an integrated service delivery model is an urgent next step, propose a South African model for integration, and conclude with recommendations for next steps in research and implementation. An approach that is inspired by South African experience would build on existing HIV-focused infrastructure that has been developed by Ministries of Health with strong support from the U.S. President's Emergency Response for AIDS Relief (PEPFAR) and the Global Fund to Fight AIDS, Tuberculosis and Malaria. An integrated chronic healthcare model holds promise to sustainably deliver infectious disease and non-communicable disease care. Integrated care will be especially critical as health systems seek to cope with the unprecedented challenges associated with COVID-19 and future pandemic threats.

Findings from a novel and scalable community-based HIV testing approach to reduce the time required to complete point-of-care HIV testing in South Africa.

BACKGROUND: Mobile HIV testing approaches are a key to reaching the global targets of halting the HIV epidemic by 2030. Importantly, the number of clients reached through mobile HIV testing approaches, need to remain high to maintain the cost-effectiveness of these approaches. Advances in rapid in-vitro tests such as INSTI® HIV-1/HIV-2 (INSTI) which uses flow-through technologies, offer opportunities to reduce the HIV testing time to about one minute. Using data from a routine mobile HTS programme which piloted the use of the INSTI point-of-care (POC) test, we sought to estimate the effect of using a faster test on client testing volumes and the number of people identified to be living with HIV, in comparison with standard of care HIV rapid tests. METHODS: In November 2019, one out of four mobile HTS teams operating in Ekurhuleni District (South Africa) was randomly selected to pilot the field use of INSTI-POC test as an HIV screening test (i.e., the intervention team). We compared the median number of clients tested for HIV and the number of HIV-positive clients by the intervention team with another mobile HTS team (matched on performance and area of operation) which used the standard of care (SOC) HIV screening test (i.e., SOC team). RESULTS: From 19 to 20 December 2019, the intervention team tested 7,403 clients, and the SOC team tested 2,426 clients. The intervention team tested a median of 442 (IQR: 288-522) clients/day; SOC team tested a median of 97 (IQR: 40-187) clients/day (p<0.0001). The intervention team tested about 180 more males/day compared to the SOC team, and the median number of adolescents and young adults tested/day by the intervention team were almost four times the number tested by the SOC team. The intervention team identified a higher number of HIV-positive clients compared to the SOC team (142 vs. 88), although the proportion of HIV-positive clients was lower in the intervention team due to the higher number of clients tested. CONCLUSIONS: This pilot programme provides evidence of high performance and high reach, for men and young people through the use of faster HIV rapid tests, by trained lay counsellors in mobile HTS units.

Effects of Dispersants and Biosurfactants on Crude-Oil Biodegradation and Bacterial Community Succession.

This study evaluated the effects of three commercial dispersants (Finasol OSR 52, Slickgone NS, Superdispersant 25) and three biosurfactants (rhamnolipid, trehalolipid, sophorolipid) in crude-oil seawater microcosms. We analysed the crucial early bacterial response (1 and 3 days). In contrast, most analyses miss this key period and instead focus on later time points after oil and dispersant addition. By focusing on the early stage, we show that dispersants and biosurfactants, which reduce the interfacial surface tension of oil and water, significantly increase the abundance of hydrocarbon-degrading bacteria, and the rate of hydrocarbon biodegradation, within 24 h. A succession of obligate hydrocarbonoclastic bacteria (OHCB), driven by metabolite niche partitioning, is demonstrated. Importantly, this succession has revealed how the OHCB Oleispira, hitherto considered to be a psychrophile, can dominate in the early stages of oil-spill response (1 and 3 days), outcompeting all other OHCB, at the relatively high temperature of 16 °C. Additionally, we demonstrate how some dispersants or biosurfactants can select for specific bacterial genera, especially the biosurfactant rhamnolipid, which appears to provide an advantageous compatibility with Pseudomonas, a genus in which some species synthesize rhamnolipid in the presence of hydrocarbons.

Extremely halophilic archaeal communities are resilient to short-term entombment in halite.

Some haloarchaea avoid the harsh conditions present in evaporating brines by entombment in brine inclusions within forming halite crystals, where a subset of haloarchaea survives over geological time. However, shifts in the community structure of halite-entombed archaeal communities remain poorly understood. Therefore, we analysed archaeal communities from in situ hypersaline brines collected from Trapani saltern (Sicily) and their successional changes in brines versus laboratory-grown halite over 21 weeks, using high-throughput sequencing. Haloarchaea were dominant, comprising >95% of the archaeal community. Unexpectedly, the OTU richness of the communities after 21 weeks was indistinguishable from the parent brine and overall archaeal abundance in halite showed no clear temporal trends. Furthermore, the duration of entombment was less important than the parent brine from which the halite derived in determining the community composition and relative abundances of most genera in halite-entombed communities. These results show that halite-entombed archaeal communities are resilient to entombment durations of up to 21 weeks, and that entombment in halite may be an effective survival strategy for near complete communities of haloarchaea. Additionally, the dominance of 'halite specialists' observed in ancient halite must occur over periods of years, rather than months, hinting at long-term successional dynamics in this environment.

Bacterial Community Legacy Effects Following the Agia Zoni II Oil-Spill, Greece.

In September 2017 the Agia Zoni II sank in the Saronic Gulf, Greece, releasing approximately 500 tonnes of heavy fuel oil, contaminating the Salamina and Athens coastlines. Effects of the spill, and remediation efforts, on sediment microbial communities were quantified over the following 7 months. Five days post-spill, the concentration of measured hydrocarbons within surface sediments of contaminated beaches was 1,093-3,773 µg g-1 dry sediment (91% alkanes and 9% polycyclic aromatic hydrocarbons), but measured hydrocarbons decreased rapidly after extensive clean-up operations. Bacterial genera known to contain oil-degrading species increased in abundance, including Alcanivorax, Cycloclasticus, Oleibacter, Oleiphilus, and Thalassolituus, and the species Marinobacter hydrocarbonoclasticus from approximately 0.02 to >32% (collectively) of the total bacterial community. Abundance of genera with known hydrocarbon-degraders then decreased 1 month after clean-up. However, a legacy effect was observed within the bacterial community, whereby Alcanivorax and Cycloclasticus persisted for several months after the oil spill in formerly contaminated sites. This study is the first to evaluate the effect of the Agia Zoni II oil-spill on microbial communities in an oligotrophic sea, where in situ oil-spill studies are rare. The results aid the advancement of post-spill monitoring models, which can predict the capability of environments to naturally attenuate oil.

Relationships among commercial practices and author conflicts of interest in biomedical publishing.

Recently, concerns have been raised over the potential impacts of commercial relationships on editorial practices in biomedical publishing. Specifically, it has been suggested that certain commercial relationships may make editors more open to publishing articles with author conflicts of interest (aCOI). Using a data set of 128,781 articles published in 159 journals, we evaluated the relationships among commercial publishing practices and reported author conflicts of interest. The 159 journals were grouped according to commercial biases (reprint services, advertising revenue, and ownership by a large commercial publishing firm). 30.6% (39,440) of articles were published in journals showing no evidence of evaluated commercial publishing relationships. 33.9% (43,630) were published in journals accepting advertising and reprint fees; 31.7% (40,887) in journals owned by large publishing firms; 1.2% (1,589) in journals accepting reprint fees only; and 2.5% (3,235) in journals accepting only advertising fees. Journals with commercial relationships were more likely to publish articles with aCOI (9.2% (92/1000) vs. 6.4% (64/1000), p = 0.024). In the multivariate analysis, only a journal's acceptance of reprint fees served as a significant predictor (OR = 2.81 at 95% CI, 1.5 to 8.6). Shared control estimation was used to evaluate the relationships between commercial publishing practices and aCOI frequency in total and by type. BCa-corrected mean difference effect sizes ranged from -1.0 to 6.1, and confirm findings indicating that accepting reprint fees may constitute the most significant commercial bias. The findings indicate that concerns over the influence of industry advertising in medical journals may be overstated, and that accepting fees for reprints may constitute the largest risk of bias for editorial decision-making.

Correction to: Coral microbiome composition along the northern Red Sea suggests high plasticity of bacterial and specificity of endosymbiotic dinoflagellate communities.

Following publication of the original article [1], the authors reported an error on the legend of of P.damicornis in Fig. 1.

Coral microbiome composition along the northern Red Sea suggests high plasticity of bacterial and specificity of endosymbiotic dinoflagellate communities.

BACKGROUND: The capacity of reef-building corals to tolerate (or adapt to) heat stress is a key factor determining their resilience to future climate change. Changes in coral microbiome composition (particularly for microalgal endosymbionts and bacteria) is a potential mechanism that may assist corals to thrive in warm waters. The northern Red Sea experiences extreme temperatures anomalies, yet corals in this area rarely bleach suggesting possible refugia to climate change. However, the coral microbiome composition, and how it relates to the capacity to thrive in warm waters in this region, is entirely unknown. RESULTS: We investigated microbiomes for six coral species (Porites nodifera, Favia favus, Pocillopora damicornis, Seriatopora hystrix, Xenia umbellata, and Sarcophyton trocheliophorum) from five sites in the northern Red Sea spanning 4° of latitude and summer mean temperature ranges from 26.6 °C to 29.3 °C. A total of 19 distinct dinoflagellate endosymbionts were identified as belonging to three genera in the family Symbiodiniaceae (Symbiodinium, Cladocopium, and Durusdinium). Of these, 86% belonged to the genus Cladocopium, with notably five novel types (19%). The endosymbiont community showed a high degree of host-specificity despite the latitudinal gradient. In contrast, the diversity and composition of bacterial communities of the surface mucus layer (SML)-a compartment particularly sensitive to environmental change-varied significantly between sites, however for any given coral was species-specific. CONCLUSION: The conserved endosymbiotic community suggests high physiological plasticity to support holobiont productivity across the different latitudinal regimes. Further, the presence of five novel algal endosymbionts suggests selection of certain genotypes (or genetic adaptation) within the semi-isolated Red Sea. In contrast, the dynamic composition of bacteria associated with the SML across sites may contribute to holobiont function and broaden the ecological niche. In doing so, SML bacterial communities may aid holobiont local acclimatization (or adaptation) by readily responding to changes in the host environment. Our study provides novel insight about the selective and endemic nature of coral microbiomes along the northern Red Sea refugia.

Impacts of long-term elevated atmospheric CO2 concentrations on communities of arbuscular mycorrhizal fungi.

The ecological impacts of long-term elevated atmospheric CO2 (eCO2 ) levels on soil microbiota remain largely unknown. This is particularly true for the arbuscular mycorrhizal (AM) fungi, which form mutualistic associations with over two-thirds of terrestrial plant species and are entirely dependent on their plant hosts for carbon. Here, we use high-resolution amplicon sequencing (Illumina, HiSeq) to quantify the response of AM fungal communities to the longest running (>15 years) free-air carbon dioxide enrichment (FACE) experiment in the Northern Hemisphere (GiFACE); providing the first evaluation of these responses from old-growth (>100 years) semi-natural grasslands subjected to a 20% increase in atmospheric CO2 . eCO2 significantly increased AM fungal richness but had a less-pronounced impact on the composition of their communities. However, while broader changes in community composition were not observed, more subtle responses of specific AM fungal taxa were with populations both increasing and decreasing in abundance in response to eCO2 . Most population-level responses to eCO2 were not consistent through time, with a significant interaction between sampling time and eCO2 treatment being observed. This suggests that the temporal dynamics of AM fungal populations may be disturbed by anthropogenic stressors. As AM fungi are functionally differentiated, with different taxa providing different benefits to host plants, changes in population densities in response to eCO2 may significantly impact terrestrial plant communities and their productivity. Thus, predictions regarding future terrestrial ecosystems must consider changes both aboveground and belowground, but avoid relying on broad-scale community-level responses of soil microbes observed on single occasions.

Are drivers of root-associated fungal community structure context specific?

The composition and structure of plant-root-associated fungal communities are determined by local abiotic and biotic conditions. However, the relative influence and identity of relationships to abiotic and biotic factors may differ across environmental and ecological contexts, and fungal functional groups. Thus, understanding which aspects of root-associated fungal community ecology generalise across contexts is the first step towards a more predictive framework. We investigated how the relative importance of biotic and abiotic factors scale across environmental and ecological contexts using high-throughput sequencing (ca. 55 M Illumina metabarcoding sequences) of >260 plant-root-associated fungal communities from six UK salt marshes across two geographic regions (South-East and North-West England) in winter and summer. Levels of root-associated fungal diversity were comparable with forests and temperate grasslands, quadrupling previous estimates of salt-marsh fungal diversity. Whilst abiotic variables were generally most important, a range of site- and spatial scale-specific abiotic and biotic drivers of diversity and community composition were observed. Consequently, predictive models of diversity trained on one site, extrapolated poorly to others. Fungal taxa from the same functional groups responded similarly to the specific drivers of diversity and composition. Thus site, spatial scale and functional group are key factors that, if accounted for, may lead to a more predictive understanding of fungal community ecology.

Household point of care CD4 testing and isoniazid preventive therapy initiation in a household TB contact tracing programme in two districts of South Africa.

BACKGROUND: In South Africa, TB household contact tracing provides an opportunity for increased TB and HIV case finding. We aimed to determine the effect of two new potential interventions for TB contact tracing programmes: Point of Care CD4 (PoC CD4) on HIV linkage to care and household Isoniazid Preventive Therapy (IPT) provision on uptake and retention of IPT. METHODS: A pragmatic, three-arm, cluster-randomized trial was undertaken. TB Household contacts were randomised to 3 arms: 1) Standard of Care TB and HIV testing (SOC); 2) SOC with POC CD4 for those testing HIV positive; 3) SOC with POC CD4 and IPT for eligible household members. Linkage to care within 90 days was assessed either through patient visits (at 10 weeks and 6 months) or via telephonic contact. RESULTS: 2,243 index TB patients and 3,012 contacts (64,3% female, median age 30 years) were enrolled. On self-report, 26(1.2%) were currently receiving TB treatment and 1816 (60.3%) reported a prior HIV test. HIV testing uptake was 34.7% in the SoC arm, 40.2% in the PoC CD4 arm (RR1.16, CI 0.99-1.36, p-value = 0.060) and 39.9% in the PoC CD4 + HH-IPT arm (RR = 1.15, CI 0.99-1.35, p-value = 0.075). Linkage to care within 3 months was 30.8% in the SoC arm and 42.1% in the POC CD4 arms (RR 1.37; CI: 0.68-2.76, p-value = 0.382). 20/21 contacts (95.2%) initiated IPT in the PoC CD4 + HH-IPT arm, compared to 3/20 (15.0%) in the PoC CD4 arm (p = 0.004; p-value from Fisher's exact test < 0.001). Among 3,008 contacts screened for tuberculosis, 15 (3.4%) had bacteriologically confirmed TB with an overall yield of TB of 0.5% (95% CI: 0.3%, 0.8%). CONCLUSIONS: Household PoC CD4 testing and IPT initiation is feasible. There was only weak evidence that PoCCD4 led to a small increase in HCT uptake and no evidence for an increase in linkage-to-care. IPT initiation and completion was increased by the household intervention. Although feasible, these interventions had low impact due to the low uptake of HIV testing in households.

Farm to Sensory Lab: Taste of Blueberry Fruit by Children and Adults.

The average American child eats fewer fruits than recommended. Although taste is the primary motivator for food intake among children, little research has systematically measured children's liking of fruit and determined whether their preferences differ from adults. We phenotyped 49 children and their mothers to determine: (1) their liking of the taste of 3 blueberry cultivars ("Arcadia," "Keecrisp," and "Kestrel") from 2 harvests for which total soluble solids were determined using a handheld Brix refractometer; (2) the association between liking and blueberry sugar content; and (3) the most preferred level of fructose, one of the primary sugars in blueberry fruit. Multiple methods, identical for all participants, assessed which cultivar they liked best. Dietary intake, determined via 24-h dietary recall, revealed most children (73%) and adults (92%) did not meet dietary guidelines for fruit intake. We found that during the 1st harvest, Keecrisp was sweeter by 4° Brix than either Arcadia or Kestrel and was the cultivar most preferred by both children and adults. For the 2nd harvest, mothers liked each of the cultivars equally, but children preferred Arcadia, which was 2° Brix sweeter than the other 2 cultivars. Like other sugars, children's most preferred concentration of fructose was significantly higher than that of adults. In sum, children appear to be more sensitive to smaller variations in sweetness than are adults. Identifying drivers of fruit preference and assessing children's liking for whole fruits are important steps in developing strategies to increase fruit consumption among children.

Soil compartment is a major determinant of the impact of simulated rainfall on desert microbiota.

Although desert soils support functionally important microbial communities that affect plant growth and influence many biogeochemical processes, the impact of future changes in precipitation patterns on the microbiota and their activities is largely unknown. We performed in-situ experiments to investigate the effect of simulated rainfall on bacterial communities associated with the widespread perennial shrub, Rhazya stricta in Arabian desert soils. The bacterial community composition was distinct between three different soil compartments: surface biological crust, root-attached, and the broader rhizosphere. Simulated rainfall had no significant effect on the overall bacterial community composition, but some population-level responses were observed, especially in soil crusts where Betaproteobacteria, Sphingobacteria, and Bacilli became more abundant. Bacterial biomass in the nutrient-rich crust increased three-fold one week after watering, whereas it did not change in the rhizosphere, despite its much higher water retention. These findings indicate that between rainfall events, desert-soil microbial communities enter into stasis, with limited species turnover, and reactivate rapidly and relatively uniformly when water becomes available. However, microbiota in the crust, which was relatively enriched in nutrients and organic matter, were primarily water-limited, compared with the rhizosphere microbiota that were co-limited by nutrients and water.

On-site treatment of exertional heat stroke.

BACKGROUND: Exertional heat stroke is a devastating condition that can cause significant morbidity and mortality. Rapid cooling is the most effective means of treating heat stroke, but little is published on the safety and logistics of cooling patients on site at a major sporting event. PURPOSE: To describe an on-site exertional heat stroke treatment protocol and to compare the outcomes of patients treated on site to those transferred to hospitals. STUDY DESIGN: Descriptive epidemiological study. METHODS: Using race-day medical records and ambulance run sheets, patients who developed exertional heat stroke at the Indianapolis half-marathon from 2005 to 2012 were identified. Exertional heat stroke was defined as runners with a core temperature measured with a rectal thermometer greater than 102° F and altered mental status. Clinical information and patient outcomes were abstracted from the race medical tent and hospital charts by 3 separate trained reviewers using structured methods and a data collection form. Two reviewers, using a RedCAP database and dual-data entry, abstracted records for each patient. A third arbitrated all discrepancies between reviewers. Clinical signs, treatments, and outcomes were calculated using descriptive statistics, and data were grouped and compared for patients treated on site or transferred to local hospitals for treatment. RESULTS: Over 235,000 athletes participated in the event over the 8-year period, with 696 seeking medical care. A total of 32 heat stroke victims were identified during the study period; of these, 22 were treated on site. Of these, 68% were treated with cold-water immersion and 59% were discharged home from the race. Ten exertional heat stroke patients were transported from the race course to local hospitals. None of them underwent cold-water immersion, and 40% of them were subsequently discharged home. No patients in the study died. CONCLUSION: On-site treatment of athletes who develop exertional heat stroke appears to be both safe and effective. On-site treatment may decrease the local burden of critically ill patients to emergency departments during large athletic events.