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Most Earth system models (ESMs) do not explicitly represent the carbon (C) costs of plant nutrient acquisition, which leads to uncertainty in predictions of the current and future constraints to the land C sink. We integrate a plant productivity-optimizing nitrogen (N) and phosphorus (P) acquisition model (fixation & uptake of nutrients, FUN) into the energy exascale Earth system (E3SM) land model (ELM). Global plant N and P uptake are dynamically simulated by ELM-FUN based on the C costs of nutrient acquisition from mycorrhizae, direct root uptake, retranslocation from senescing leaves, and biological N fixation. We benchmarked ELM-FUN with three classes of products: ILAMB, a remotely sensed nutrient limitation product, and CMIP6 models; we found significant improvements in C cycle variables, although the lack of more observed nutrient data prevents a comprehensive level of benchmarking. Overall, we found N and P co-limitation for 80% of land area, with the remaining 20% being either predominantly N or P limited. Globally, the new model predicts that plants invested 4.1 Pg C yr-1 to acquire 841.8 Tg N yr-1 and 48.1 Tg P yr-1 (1994-2005), leading to significant downregulation of global net primary production (NPP). Global NPP is reduced by 20% with C costs of N and 50% with C costs of NP. Modeled and observed nutrient limitation agreement increases when N and P are considered together (r 2 from 0.73 to 0.83).

© Author(s) 2017. How carbon (C) is allocated to different plant tissues (leaves, stem, and roots) determines how long C remains in plant biomass and thus remains a central challenge for understanding the global C cycle. We used a diverse set of observations (AmeriFlux eddy covariance tower observations, biomass estimates from tree-ring data, and leaf area index (LAI) measurements) to compare C fluxes, pools, and LAI data with those predicted by a land surface model (LSM), the Community Land Model (CLM4.5). We ran CLM4.5 for nine temperate (including evergreen and deciduous) forests in North America between 1980 and 2013 using four different C allocation schemes: dynamic C allocation scheme (named "D-CLM4.5") with one dynamic allometric parameter, which allocates C to the stem and leaves to vary in time as a function of annual net primary production (NPP); ii. an alternative dynamic C allocation scheme (named "DLitton"), where, similar to (i), C allocation is a dynamic function of annual NPP, but unlike (i) includes two dynamic allometric parameters involving allocation to leaves, stem, and coarse roots; iii.-iv. a fixed C allocation scheme with two variants, one representative of observations in evergreen (named "F Evergreen") and the other of observations in deciduous forests (named "F-Deciduous"). D-CLM4.5 generally overestimated gross primary production (GPP) and ecosystem respiration, and underestimated net ecosystem exchange (NEE). In D-CLM4.5, initial aboveground biomass in 1980 was largely overestimated (between 10 527 and 12 897 g Cm-2) for deciduous forests, whereas aboveground biomass accumulation through time (between 1980 and 2011) was highly underestimated (between 1222 and 7557 gCm-2) for both evergreen and deciduous sites due to a lower stem turnover rate in the sites than the one used in the model. D-CLM4.5 overestimated LAI in both evergreen and deciduous sites because the leaf C-LAI relationship in the model did not match the observed leaf C- LAI relationship at our sites. Although the four C allocation schemes gave similar results for aggregated C fluxes, they translated to important differences in long-term aboveground biomass accumulation and aboveground NPP. For deciduous forests, D-Litton gave more realistic Cstem- Cleafratios and strongly reduced the overestimation of initial aboveground biomass and aboveground NPP for deciduous forests by D-CLM4.5. We identified key structural and parameterization deficits that need refinement to improve the accuracy of LSMs in the near future. These include changing how C is allocated in fixed and dynamic schemes based on data from current forest syntheses and different parameterization of allocation schemes for different forest types.Our results highlight the utility of using measurements of aboveground biomass to evaluate and constrain the C allocation scheme in LSMs, and suggest that stem turnover is overestimated by CLM4.5 for these AmeriFlux sites. Understanding the controls of turnover will be critical to improving long-term C processes in LSMs.

Aims. We studied the quality of opportunistic screening for diabetic retinopathy, which existed in the absence of a formal screening programme. Methods. Patients referred during the period from June 1992 to May 1997 were identified. The findings and outcome at first ophthalmic consultation were used as surrogate measures to determine the appropriateness of referral. We considered patients to have had sight-threatening retinopathy (STDR) if laser treatment or fluorescein angiography was recommended, or follow-up at 6 months or less was arranged. Patients whose fundi could not be visualised were also included in the STDR group. Results. Two hundred and eighty-nine case records were available for analysis; 190 of these (65.7%) were considered to have STDR and 41 (14.2%) had other pathology, without concurrent diabetic retinopathy. The agreement between the referrer's diagnosis and the diagnosis made by the ophthalmologist was only fair, when comparing major diagnostic categories (kappa 0.35, 95% CI 0.30-0.41) and also for grading of retinopathy (kappa 0.30, 95% CI 0.23-0.37). Conclusions. Our findings suggest that opportunistic screening can identify retinopathy only at a late stage. Our data should be valuable in measuring the benefits of formal screening for diabetic retinopathy as compared to previously existing services. Copyright © 2001 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

It is well-known that the mycorrhizal type of plants correlates with different modes of nutrient cycling and availability. However, the differences in drought tolerance between arbuscular mycorrhizal (AM) and ectomycorrhizal (EcM) plants remains poorly characterized. We synthesized a global dataset of four hydraulic traits associated with drought tolerance of 1457 woody species (1139 AM and 318 EcM species) at 308 field sites. We compared these traits between AM and EcM species, with evolutionary history (i.e. angiosperms vs gymnosperms), water availability (i.e. aridity index) and biomes considered as additional factors. Overall, we found that evolutionary history and biogeography influenced differences in hydraulic traits between mycorrhizal types. Specifically, we found that (1) AM angiosperms are less drought-tolerant than EcM angiosperms in wet regions or biomes, but AM gymnosperms are more drought-tolerant than EcM gymnosperms in dry regions or biomes, and (2) in both angiosperms and gymnosperms, variation in hydraulic traits as well as their sensitivity to water availability were higher in AM species than in EcM species. Our results suggest that global shifts in water availability (especially drought) may alter the biogeographic distribution and abundance of AM and EcM plants, with consequences for ecosystem element cycling and ultimately, the land carbon sink., (© 2024 The Author(s). New Phytologist © 2024 New Phytologist Foundation.)

Sepsis is the second leading cause of pregnancy-related mortality in the United States. Early recognition, treatment, and escalation of care for the obstetric patient affected by sepsis mitigate the risk of mortality and improve patient outcomes. In this article, we provide an overview of maternal sepsis and address topics of maternal pathophysiology, early warning signs, diagnostic criteria, early goal-directed therapy, and contemporary critical care practices. We also present an overview of common etiologies of maternal sepsis and suggested treatment approaches., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Forests around the world are experiencing changes due to climate variability and human land use. How these changes interact and influence the vulnerability of forests are not well understood. In the eastern United States, well-documented anthropogenic disturbances and land-use decisions, such as logging and fire suppression, have influenced forest species assemblages, leading to a demographic shift from forests dominated by xeric species to those dominated by mesic species. Contemporarily, the climate has changed and is expected to continue to warm and produce higher evaporative demand, imposing stronger drought stress on forest communities. Here, we use an extensive network of tree-ring records from common hardwood species across ~100 sites and ~1300 trees in the eastern United States to examine the magnitude of growth response to both wet and dry climate extremes. We find that growth reductions during drought exceed the positive growth response to pluvials. Mesic species such as Liriodendron tulipifera and Acer saccharum, which are becoming more dominant, are more sensitive to drought than more xeric species, such as oaks (Quercus) and hickory (Carya), especially at moderate and extreme drought intensities. Although more extreme droughts produce a larger annual growth reduction, mild droughts resulted in the largest cumulative growth decreases due to their higher frequency. When using global climate model projections, all scenarios show drought frequency increasing substantially (3-9 times more likely) by 2100. Thus, the ongoing demographic shift toward more mesic species in the eastern United States combined with drier conditions results in larger drought-induced growth declines, suggesting that drought will have an even larger impact on aboveground carbon uptake in the future in the eastern United States., (© 2024 The Author(s). Global Change Biology published by John Wiley & Sons Ltd.)

Objective: This study aims to determine if pregnant patients with both pyelonephritis and anemia are at an increased risk of adverse maternal outcomes compared with those with pyelonephritis without anemia., Study Design: We conducted a retrospective cohort study utilizing the Nationwide Readmissions Database (NRD). Patients with antepartum pyelonephritis-associated hospitalizations from October 2015 to December 2018 were included. International Classification of Diseases codes were used to identify pyelonephritis, anemia, maternal comorbidities, and severe maternal morbidities. The primary outcome was a composite of severe maternal morbidity, as defined by the Centers for Disease Control criteria. Univariate statistical methods, weighted to account for complex survey methods in the NRD, were used to assess for associations between anemia, baseline characteristics, and patient outcomes. Weighted logistic and Poisson regressions were used to assess for associations between anemia and outcomes, adjusting for clinical comorbidities and other confounding factors., Results: In total, 29,296 pyelonephritis admissions were identified, corresponding to a weighted national estimate of 55,135 admissions. Of these, 11,798 (21.3%) were anemic. The rate of severe maternal morbidity was higher among anemic patients than nonanemic patients (27.8 vs. 8.9%, respectively, p  < 0.001), and remained higher after adjustment (adjusted relative risk [aRR] 2.86 [95% confidence interval [CI]: 2.67, 3.06]). Rates of individual components of severe maternal morbidities, including acute respiratory distress syndrome (4.0 vs. 0.6%, aRR 3.97 [95% CI: 3.10, 5.08]), sepsis (22.5 vs. 7.9%, aRR 2.64 [95% CI: 2.45, 2.85]), shock (4.5 vs. 0.6%, aRR 5.48 [95% CI: 4.32, 6.95]), and acute renal failure (2.9 vs. 0.8%, aRR 1.99 [95% CI: 1.55, 2.55]) were all higher for anemic pyelonephritis. The mean length of stay was also longer (25% average increase, 95% CI: 22, 28%)., Conclusion: Among pregnant patients with pyelonephritis, those with anemia are at greater risk of severe maternal morbidity and longer hospital stay., Key Points: · Anemia is associated with longer stays for pyelo.. · Anemic pyelo patients have increased morbidity.. · Anemic pyelo patients have increased sepsis risk.., Competing Interests: None declared., (Thieme. All rights reserved.)

Fine root lifespan is a critical trait associated with contrasting root strategies of resource acquisition and protection. Yet, its position within the multidimensional "root economics space" synthesizing global root economics strategies is largely uncertain, and it is rarely represented in frameworks integrating plant trait variations. Here, we compiled the most comprehensive dataset of absorptive median root lifespan (MRL) data including 98 observations from 79 woody species using (mini-)rhizotrons across 40 sites and linked MRL to other plant traits to address questions of the regulators of MRL at large spatial scales. We demonstrate that MRL not only decreases with plant investment in root nitrogen (associated with more metabolically active tissues) but also increases with construction of larger diameter roots which is often associated with greater plant reliance on mycorrhizal symbionts. Although theories linking organ structure and function suggest that root traits should play a role in modulating MRL, we found no correlation between root traits associated with structural defense (root tissue density and specific root length) and MRL. Moreover, fine root and leaf lifespan were globally unrelated, except among evergreen species, suggesting contrasting evolutionary selection between leaves and roots facing contrasting environmental influences above vs. belowground. At large geographic scales, MRL was typically longer at sites with lower mean annual temperature and higher mean annual precipitation. Overall, this synthesis uncovered several key ecophysiological covariates and environmental drivers of MRL, highlighting broad avenues for accurate parametrization of global biogeochemical models and the understanding of ecosystem response to global climate change., Competing Interests: Competing interests statement:The authors declare no competing interest.

Numerous studies have shown reduced performance in plants that are surrounded by neighbours of the same species 1,2 , a phenomenon known as conspecific negative density dependence (CNDD) 3 . A long-held ecological hypothesis posits that CNDD is more pronounced in tropical than in temperate forests 4,5 , which increases community stabilization, species coexistence and the diversity of local tree species 6,7 . Previous analyses supporting such a latitudinal gradient in CNDD 8,9 have suffered from methodological limitations related to the use of static data 10-12 . Here we present a comprehensive assessment of latitudinal CNDD patterns using dynamic mortality data to estimate species-site-specific CNDD across 23 sites. Averaged across species, we found that stabilizing CNDD was present at all except one site, but that average stabilizing CNDD was not stronger toward the tropics. However, in tropical tree communities, rare and intermediate abundant species experienced stronger stabilizing CNDD than did common species. This pattern was absent in temperate forests, which suggests that CNDD influences species abundances more strongly in tropical forests than it does in temperate ones 13 . We also found that interspecific variation in CNDD, which might attenuate its stabilizing effect on species diversity 14,15 , was high but not significantly different across latitudes. Although the consequences of these patterns for latitudinal diversity gradients are difficult to evaluate, we speculate that a more effective regulation of population abundances could translate into greater stabilization of tropical tree communities and thus contribute to the high local diversity of tropical forests., (© 2024. The Author(s).)

Objective  Group B Streptococcus (GBS) colonization of the lower urinary tract in pregnancy is associated with severe infections such as chorioamnionitis, endometritis, and pyelonephritis. The objective of this study was to compare rates of progression to pyelonephritis between GBS and Escherichia coli lower urinary tract infections (LUTIs), as well as compare infectious and obstetric morbidity secondary to these pathogens. Study Design  Retrospective cohort of pregnant women with LUTIs (asymptomatic bacteria or acute cystitis [AC]) from a single health system between July 2013 and May 2019. Demographic, infectious, antepartum, and intrapartum data were abstracted from medical records of women with GBS or E. coli LUTI. The primary outcome was progression to pyelonephritis. Secondary outcomes included pyelonephritis-related anemia, sepsis, pyelonephritis length of stay (LOS), median gestational age (GA) at delivery, preterm delivery, and low birth weight (LBW). Logistic regression was used to calculate the adjusted odds of the primary outcome. Results  Of 729 pregnant women with urinary colonization, 433 were culture positive for one of the aforementioned bacteria, with 189 (43.6%) having GBS and 244 (56.4%) having E. coli. Women with E. coli were more likely to be younger, use tobacco, have a history of AC, and have a history of preterm birth. Rates of progression to pyelonephritis were markedly higher with E. coli (15.6%) than with GBS (1.1%; p  < 0.001). Median LOS for pyelonephritis and pyelonephritis-related morbidities did not differ. Median GA at delivery, preterm delivery, and LBW rates also did not differ. In adjusted analysis, controlling for history of AC, insurance status, tobacco use, prior preterm birth, primary infection type, and maternal age, women with GBS LUTI had markedly decreased odds of developing pyelonephritis in pregnancy compared with those with E. coli (adjusted odds ratio: 0.04, 95% confidence interval: 0.01-0.28). Conclusion   Escherichia coli infections progress to pyelonephritis in pregnancy at markedly higher rates than GBS, although obstetric outcomes are similar., Competing Interests: Conflict of Interest None declared., (The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. ( https://creativecommons.org/licenses/by-nc-nd/4.0/ ).)

Climate change is increasing the frequency and severity of short-term (~1 y) drought events-the most common duration of drought-globally. Yet the impact of this intensification of drought on ecosystem functioning remains poorly resolved. This is due in part to the widely disparate approaches ecologists have employed to study drought, variation in the severity and duration of drought studied, and differences among ecosystems in vegetation, edaphic and climatic attributes that can mediate drought impacts. To overcome these problems and better identify the factors that modulate drought responses, we used a coordinated distributed experiment to quantify the impact of short-term drought on grassland and shrubland ecosystems. With a standardized approach, we imposed ~a single year of drought at 100 sites on six continents. Here we show that loss of a foundational ecosystem function-aboveground net primary production (ANPP)-was 60% greater at sites that experienced statistically extreme drought (1-in-100-y event) vs. those sites where drought was nominal (historically more common) in magnitude (35% vs. 21%, respectively). This reduction in a key carbon cycle process with a single year of extreme drought greatly exceeds previously reported losses for grasslands and shrublands. Our global experiment also revealed high variability in drought response but that relative reductions in ANPP were greater in drier ecosystems and those with fewer plant species. Overall, our results demonstrate with unprecedented rigor that the global impacts of projected increases in drought severity have been significantly underestimated and that drier and less diverse sites are likely to be most vulnerable to extreme drought., Competing Interests: Competing interests statement:The authors declare no competing interest.

The emergence of billions of periodical cicadas affects plant and animal communities profoundly, yet little is known about cicada impacts on soil carbon fluxes. We investigated the effects of Brood X cicadas (Magicicada septendecim, M. cassinii and M. septendeculain) on soil CO 2 fluxes (R S ) in three Indiana forests. We hypothesized R S would be sensitive to emergence hole density, with the greatest effects occurring in soils with the lowest ambient fluxes. In support of our hypothesis, R S increased with increasing hole density and greater effects were observed near AM-associating trees (which expressed lower ambient fluxes) than near EcM-associating trees. Additionally, R S from emergence holes increased the temperature sensitivity (Q 10 ) of R S by 13%, elevating the Q 10 of ecosystem respiration. Brood X cicadas increased annual R S by ca. 2.5%, translating to an additional 717 Gg of CO 2 across forested areas. As such, periodical cicadas can have substantial effects on soil processes and biogeochemistry., (© 2024 John Wiley & Sons Ltd.)

One mechanism proposed to explain high species diversity in tropical systems is strong negative conspecific density dependence (CDD), which reduces recruitment of juveniles in proximity to conspecific adult plants. Although evidence shows that plant-specific soil pathogens can drive negative CDD, trees also form key mutualisms with mycorrhizal fungi, which may counteract these effects. Across 43 large-scale forest plots worldwide, we tested whether ectomycorrhizal tree species exhibit weaker negative CDD than arbuscular mycorrhizal tree species. We further tested for conmycorrhizal density dependence (CMDD) to test for benefit from shared mutualists. We found that the strength of CDD varies systematically with mycorrhizal type, with ectomycorrhizal tree species exhibiting higher sapling densities with increasing adult densities than arbuscular mycorrhizal tree species. Moreover, we found evidence of positive CMDD for tree species of both mycorrhizal types. Collectively, these findings indicate that mycorrhizal interactions likely play a foundational role in global forest diversity patterns and structure., (© 2023. Springer Nature Limited.)

Objective: Hepatitis C virus and intrahepatic cholestasis of pregnancy (ICP) are well-known independent risk factors for adverse outcomes in pregnancy. In addition, it is well-established that there is an association between Hepatitis C and ICP. This study's objective was to describe the impact of having both Hepatitis C and ICP on maternal and obstetric outcomes compared to patients having either Hepatitis C or ICP., Methods: We conducted a retrospective cohort study of the Nationwide Readmissions Database, an all-payor sample of discharges from approximately 60% of US hospitalizations. Deliveries at 24-42+ weeks between 10/2015 and 12/2020 were included. Diagnosis of Hepatitis C and ICP, and outcomes related to severe maternal morbidity were identified using International Classification of Disease-10 codes. Patients were categorized based on Hepatitis C and ICP status. Weighted logistic and negative binomial regression analyses were used to evaluate the association between Hepatitis C and ICP status and outcomes, adjusting for patient and hospital characteristics. The primary outcome was any severe maternal morbidity; secondary outcomes included acute respiratory distress syndrome, acute kidney injury, sepsis, gestational diabetes, cesarean delivery, preterm birth, and hospital length of stay. We modeled interaction terms between ICP and Hepatitis C to assess whether there was a greater or lesser effect from having both conditions on outcomes than we would expect from additive combination of the individual components (i.e., synergy or antagonism)., Results: A total of 10,040,850 deliveries between 24-42+ weeks were identified. Of these, 45,368 had Hepatitis C only; 84,582 had ICP only; and 1,967 had both Hepatitis C and ICP. Patients with both Hepatitis C and ICP had 1.5-fold higher odds of developing severe maternal morbidity compared to having neither. There was an also an increased odds of severe maternal morbidity in patients with both Hepatitis C and ICP compared to patients with only Hepatitis C or ICP. Having both was also associated with higher odds of preterm birth and length of stay compared to having only Hepatitis C, only ICP, or neither (preterm birth: aOR 5.09, 95% CI 4.87-5.33 vs. neither; length of stay: 46% mean increase, 95% CI 35-58% vs. neither). Associations were additive-no significant interactions between hepatitis C and cholestasis were found on rates of severe maternal morbidity, acute respiratory distress syndrome, acute kidney injury, sepsis, cesarean section, or preterm birth (all p>0.05), and was minimal for gestational diabetes and length of stay., Conclusion: Hepatitis C and ICP are independent, additive risk factors for adverse maternal and obstetric outcomes. Despite physiologic plausibility, no evidence of a synergistic effect of these two diagnoses on outcomes was noted. These data may be useful in counseling patients regarding their increased risk of adverse outcomes when ICP presents in association with Hepatitis C versus ICP alone., Competing Interests: The authors report no conflict of interest., (Copyright: © 2023 Goins et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Decades of theory and empirical studies have demonstrated links between biodiversity and ecosystem functioning, yet the putative processes that underlie these patterns remain elusive. This is especially true for forest ecosystems, where the functional traits of plant species are challenging to quantify. We analyzed 74,563 forest inventory plots that span 35 ecoregions in the contiguous USA and found that in ~77% of the ecoregions mixed mycorrhizal plots were more productive than plots where either arbuscular or ectomycorrhizal fungal-associated tree species were dominant. Moreover, the positive effects of mixing mycorrhizal strategies on forest productivity were more pronounced at low than high tree species richness. We conclude that at low richness different mycorrhizal strategies may allow tree species to partition nutrient uptake and thus can increase community productivity, whereas at high richness other dimensions of functional diversity can enhance resource partitioning and community productivity. Our findings highlight the importance of mixed mycorrhizal strategies, in addition to that of taxonomic diversity in general, for maintaining ecosystem functioning in forests., (© 2023. The Author(s).)

Importance: Group B Streptococcus (GBS) is a common pathogen with an effective treatment. However, it remains a significant cause of neonatal sepsis, morbidity, and mortality. The screening and management of this infection are some of the first concepts learned during medical training in obstetrics. However, effective screening and evidence-based management of GBS are nuanced with many critical caveats., Objective: The objectives of this review are to discuss the essential aspects of GBS screening and management and to highlight recent changes to recommendations and guidelines., Evidence Acquisition: Original research articles, review articles, and guidelines on GBS were reviewed., Results: The following recommendations are based on review of the evidence and professional society guidelines. Screening for GBS should occur between 36 weeks and the end of the 37th week. The culture swab should go 2 cm into the vagina and 1 cm into the anus. Patients can perform their own swabs as well. Penicillin allergy testing has been shown to be safe in pregnancy. Patients with GBS in the urine should be treated at term with antibiotic prophylaxis, independent of the colony count of the culture. Patients who are GBS-positive with preterm and prelabor rupture of membranes after 34 weeks are not candidates for expectant management, as this population has higher rates of neonatal infectious complications. Patients with a history of GBS colonization in prior pregnancy who are GBS-unknown in this current pregnancy and present with labor should receive intrapartum prophylaxis. Work on the GBS vaccine continues., Conclusions: Although all of the efforts and focus on neonatal early-onset GBS infection have led to lower rates of disease, GBS still remains a major cause of neonatal morbidity and mortality requiring continued vigilance from obstetric providers.

The microbial priming effect-the decomposition of soil organic carbon (SOC) induced by plant inputs-has long been considered an important driver of SOC dynamics, yet we have limited understanding about the direction, intensity, and drivers of priming across ecosystem types and biomes. This gap hinders our ability to predict how shifts in litter inputs under global change can affect climate feedbacks. Here, we synthesized 18,919 observations of CO 2 effluxes in 802 soils across the globe to test the relative effects (i.e., log response ratio [RR]) of litter additions on native SOC decomposition and identified the dominant environmental drivers in natural ecosystems and agricultural lands. Globally, litter additions enhanced native SOC decomposition (RR = 0.35, 95% CI: 0.32-0.38), with greater priming effects occurring with decreasing latitude and more in agricultural soils (RR = 0.43) than in uncultivated soils (RR = 0.28). In natural ecosystems, soil pH and microbial community composition (e.g., bacteria: fungi ratio) were the best predictors of priming, with greater effects occurring in acidic, bacteria-dominated sandy soils. In contrast, the substrate properties of plant litter and soils were the most important drivers of priming in agricultural systems since soils with high C:N ratios and those receiving large inputs of low-quality litter had the highest priming effects. Collectively, our results suggest that, though different factors may control priming effects, the ubiquitous nature of priming means that alterations of litter quality and quantity owing to global changes will likely have consequences for global C cycling and climate forcing., (© 2022 The Ecological Society of America.)

First principles predict that diversity at one trophic level often begets diversity at other levels, suggesting plant and mycorrhizal fungal diversity should be coupled. Local-scale studies have shown positive coupling between the two, but the association is less consistent when extended to larger spatial and temporal scales. These inconsistencies are likely due to divergent relationships of different mycorrhizal fungal guilds to plant diversity, scale dependency, and a lack of coordinated sampling efforts. Given that mycorrhizal fungi play a central role in plant productivity and nutrient cycling, as well as ecosystem responses to global change, an improved understanding of the coupling between plant and mycorrhizal fungal diversity across scales will reduce uncertainties in predicting the ecosystem consequences of species gains and losses., (© 2022 The Authors. New Phytologist © 2022 New Phytologist Foundation This article has been contributed to by US Government employees and their work is in the public domain in the USA.)

Objective: Outside of pregnancy, urinary pathogens such as Proteus and Klebsiella are considered more pathogenic than E. coli . During pregnancy, the implications of lower urinary tract infection (LUTI) with more pathogenic bacteria are unclear. Thus, we sought to compare the risk of progression from LUTI to pyelonephritis among women infected with these more pathogenic urinary bacteria to those infected with E. coli ., Study Design: Retrospective cohort of pregnant women with LUTI at single tertiary center from July 2013 to May 2019. Pathogenic infections (PI) were defined as asymptomatic bacteriuria or acute cystitis urinary cultures positive for Proteus , Klebsiella , Enterobacter , Citrobacter , Acinetobacter , Staphylococcus , or Raoultella species. Demographic, infectious, antepartum, and postpartum data abstracted. Pregnant women with PI compared with those with E. coli . Primary outcome was progression to pyelonephritis. Secondary outcomes included pyelonephritis length of stay (LOS) >6 days, preterm birth (PTB), low birthweight (LBW), and measures of pyelonephritis-related morbidity., Results: Of 686 pregnant women with LUTIs, 313 had urine culture growing out either PI or E. coli , with 59 (12%) growing PI and 254 (54%) growing E. coli . Women with PI were more likely to be African American, have chronic hypertension, and have history of preeclampsia. The primary species causing PI were Klebsiella ( n  = 29) and Proteus ( n  = 11). PI were not more likely to progress to pyelonephritis than E. coli LUTIs (10.9 vs. 14.5%; p  = 0.67). Median LOS for pyelonephritis and other measures of pyelonephritis-related morbidity did not differ nor did PTB or LBW rates. After controlling for race, body mass index, history of preeclampsia, and history of pyelonephritis, PI were not associated with increased odds of progression to pyelonephritis (adjusted odds ratio: 0.69, 95% confidence interval: 0.27-1.80)., Conclusion: Bacteria traditionally considered to be more pathogenic outside of pregnancy do not progress to pyelonephritis at higher rates than E. coli in pregnancy, and are associated with similar pyelonephritis-related morbidity. Larger studies are needed to confirm these findings., Key Points: · Little is known about impact of uropathogen on progression to pyelonephritis and obstetric outcomes.. · Rates of progression to pyelonephritis from UTI did not vary by uropathogen.. · Pyelonephritis-related morbidities and preterm birth rates were also similar among uropathogens.., Competing Interests: None declared., (Thieme. All rights reserved.)

Conceptual and empirical advances in soil biogeochemistry have challenged long-held assumptions about the role of soil micro-organisms in soil organic carbon (SOC) dynamics; yet, rigorous tests of emerging concepts remain sparse. Recent hypotheses suggest that microbial necromass production links plant inputs to SOC accumulation, with high-quality (i.e., rapidly decomposing) plant litter promoting microbial carbon use efficiency, growth, and turnover leading to more mineral stabilization of necromass. We test this hypothesis experimentally and with observations across six eastern US forests, using stable isotopes to measure microbial traits and SOC dynamics. Here we show, in both studies, that microbial growth, efficiency, and turnover are negatively (not positively) related to mineral-associated SOC. In the experiment, stimulation of microbial growth by high-quality litter enhances SOC decomposition, offsetting the positive effect of litter quality on SOC stabilization. We suggest that microbial necromass production is not the primary driver of SOC persistence in temperate forests. Factors such as microbial necromass origin, alternative SOC formation pathways, priming effects, and soil abiotic properties can strongly decouple microbial growth, efficiency, and turnover from mineral-associated SOC., (© 2022. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

The coordination of plant leaf water potential (Ψ L ) regulation and xylem vulnerability to embolism is fundamental for understanding the tradeoffs between carbon uptake and risk of hydraulic damage. There is a general consensus that trees with vulnerable xylem more conservatively regulate Ψ L than plants with resistant xylem. We evaluated if this paradigm applied to three important eastern US temperate tree species, Quercus alba L., Acer saccharum Marsh. and Liriodendron tulipifera L., by synthesizing 1600 Ψ L observations, 122 xylem embolism curves and xylem anatomical measurements across 10 forests spanning pronounced hydroclimatological gradients and ages. We found that, unexpectedly, the species with the most vulnerable xylem (Q. alba) regulated Ψ L less strictly than the other species. This relationship was found across all sites, such that coordination among traits was largely unaffected by climate and stand age. Quercus species are perceived to be among the most drought tolerant temperate US forest species; however, our results suggest their relatively loose Ψ L regulation in response to hydrologic stress occurs with a substantial hydraulic cost that may expose them to novel risks in a more drought-prone future., (© 2021 John Wiley & Sons Ltd.)

Trees associating with different mycorrhizas often differ in their effects on litter decomposition, nutrient cycling, soil organic matter (SOM) dynamics, and plant-soil interactions. For example, due to differences between arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) tree leaf and root traits, ECM-associated soil has lower rates of C and N cycling and lower N availability than AM-associated soil. These observations suggest that many groups of nonmycorrhizal fungi should be affected by the mycorrhizal associations of dominant trees through controls on nutrient availability. To test this overarching hypothesis, we explored the influence of predominant forest mycorrhizal type and mineral N availability on soil fungal communities using next-generation amplicon sequencing. Soils from four temperate hardwood forests in southern Indiana, United States, were studied; three forests formed a natural gradient of mycorrhizal dominance (100% AM tree basal area to 100% ECM basal area), while the fourth forest contained a factorial experiment testing long-term N addition in both dominant mycorrhizal types. We found that overall fungal diversity, as well as the diversity and relative abundance of plant pathogenic and saprotrophic fungi, increased with greater AM tree dominance. Additionally, tree community mycorrhizal associations explained more variation in fungal community composition than abiotic variables, including soil depth, SOM content, nitrification rate, and mineral N availability. Our findings suggest that tree mycorrhizal associations may be good predictors of the diversity, composition, and functional potential of soil fungal communities in temperate hardwood forests. These observations help explain differing biogeochemistry and community dynamics found in forest stands dominated by differing mycorrhizal types. IMPORTANCE Our work explores how differing mycorrhizal associations of temperate hardwood trees (i.e., arbuscular [AM] versus ectomycorrhizal [ECM] associations) affect soil fungal communities by altering the diversity and relative abundance of saprotrophic and plant-pathogenic fungi along natural gradients of mycorrhizal dominance. Because temperate hardwood forests are predicted to become more AM dominant with climate change, studies examining soil communities along mycorrhizal gradients are necessary to understand how these global changes may alter future soil fungal communities and their functional potential. Ours, along with other recent studies, identify possible global trends in the frequency of specific fungal functional groups responsible for nutrient cycling and plant-soil interactions as they relate to mycorrhizal associations.

Biogenic volatile organic compounds (BVOCs) play critical roles in ecological and earth-system processes. Ecosystem BVOC models rarely include soil and litter fluxes and their accuracy is often challenged by BVOC dynamics during periods of rapid ecosystem change like spring leaf out. We measured BVOC concentrations within the air space of a mixed deciduous forest and used a hybrid Lagrangian/Eulerian canopy transport model to estimate BVOC flux from the forest floor, canopy, and whole ecosystem during spring. Canopy flux measurements were dominated by a large methanol source and small isoprene source during the leaf-out period, consistent with past measurements of leaf ontogeny and theory, and indicative of a BVOC flux situation rarely used in emissions model testing. The contribution of the forest floor to whole-ecosystem BVOC flux is conditional on the compound of interest and is often non-trivial. We created linear models of forest floor, canopy, and whole-ecosystem flux for each study compound and used information criteria-based model selection to find the simplest model with the best fit. Most published BVOC flux models do not include vapor pressure deficit (VPD), but it entered the best canopy, forest floor, and whole-ecosystem BVOC flux model more than any other study variable in the present study. Since VPD is predicted to increase in the future, future studies should investigate how it contributes to BVOC flux through biophysical mechanisms like evaporative demand, leaf temperature and stomatal function., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

There is increasing evidence that plant roots and mycorrhizal fungi, whether living or dead, play a central role in soil carbon (C) cycling. Root-mycorrhizal-microbial interactions can both suppress and enhance litter decay, with the net result dependent upon belowground nutrient acquisition strategies and soil nutrient availability. We measured the net effect of living roots and mycorrhizal fungi on the decay of dead roots and fungal hyphae in a hardwood forest dominated by either sugar maple (Acer saccharum) or white oak (Quercus alba) trees. Root and fungal litter were allowed to decompose within root-ingrowth bags and root-exclusion cores. In conjunction with root effects on decay, we assessed foraging responses and root induced changes in soil moisture, nitrogen (N) availability and enzyme activity. After 1 year, maple root production increased, and mycorrhizal fungal colonization decreased in the presence of decaying litter. In addition, we found that actively foraging roots suppressed the decay of root litter (- 14%) more than fungal litter (- 3%), and suppression of root decay was stronger for oak (- 20%) than maple roots (- 8%). Suppressive effects of oak roots on decay were greatest when roots also reduced soil N availability, which corresponded with reductions in hydrolytic enzyme activity and enhanced oxidative enzyme activities. These findings further our understanding of context-dependent drivers of root-mycorrhizal-microbial interactions and demonstrate that such interactions can play an underappreciated role in soil organic matter accumulation and turnover in temperate forests., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The leaf economics spectrum 1,2 and the global spectrum of plant forms and functions 3 revealed fundamental axes of variation in plant traits, which represent different ecological strategies that are shaped by the evolutionary development of plant species 2 . Ecosystem functions depend on environmental conditions and the traits of species that comprise the ecological communities 4 . However, the axes of variation of ecosystem functions are largely unknown, which limits our understanding of how ecosystems respond as a whole to anthropogenic drivers, climate and environmental variability 4,5 . Here we derive a set of ecosystem functions 6 from a dataset of surface gas exchange measurements across major terrestrial biomes. We find that most of the variability within ecosystem functions (71.8%) is captured by three key axes. The first axis reflects maximum ecosystem productivity and is mostly explained by vegetation structure. The second axis reflects ecosystem water-use strategies and is jointly explained by variation in vegetation height and climate. The third axis, which represents ecosystem carbon-use efficiency, features a gradient related to aridity, and is explained primarily by variation in vegetation structure. We show that two state-of-the-art land surface models reproduce the first and most important axis of ecosystem functions. However, the models tend to simulate more strongly correlated functions than those observed, which limits their ability to accurately predict the full range of responses to environmental changes in carbon, water and energy cycling in terrestrial ecosystems 7,8 ., (© 2021. The Author(s).)

Microbial processes play a central role in controlling the availability of N in temperate forests. While bacteria, archaea, and fungi account for major inputs, transformations, and exports of N in soil, relationships between microbial community structure and N cycle fluxes have been difficult to detect and characterize. Several studies have reported differences in N cycling based on mycorrhizal type in temperate forests, but associated differences in N cycling genes underlying these fluxes are not well-understood. We explored how rates of soil N cycle fluxes vary across gradients of mycorrhizal abundance (hereafter "mycorrhizal gradients") at four temperate forest sites in Massachusetts and Indiana, USA. We paired measurements of N-fixation, net nitrification, and denitrification rates with gene abundance data for specific bacterial functional groups associated with each process. We find that the availability of NO 3 and rates of N-fixation, net nitrification, and denitrification are reduced in stands dominated by trees associated with ECM fungi. On average, rates of N-fixation and denitrification in stands dominated by trees associated with arbuscular mycorrhizal fungi were more than double the corresponding rates in stands dominated by trees associated with ectomycorrhizal fungi. Despite the structuring of flux rates across the mycorrhizal gradients, we did not find concomitant shifts in the abundances of N-cycling bacterial genes, and gene abundances were not correlated with process rates. Given that AM-associating trees are replacing ECM-associating trees throughout much of the eastern US, our results suggest that shifts in mycorrhizal dominance may accelerate N cycling independent of changes in the relative abundance of N cycling bacteria, with consequences for forest productivity and N retention., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Terrestrial ecosystems remove about 30 per cent of the carbon dioxide (CO 2 ) emitted by human activities each year 1 , yet the persistence of this carbon sink depends partly on how plant biomass and soil organic carbon (SOC) stocks respond to future increases in atmospheric CO 2 (refs. 2,3 ). Although plant biomass often increases in elevated CO 2 (eCO 2 ) experiments 4-6 , SOC has been observed to increase, remain unchanged or even decline 7 . The mechanisms that drive this variation across experiments remain poorly understood, creating uncertainty in climate projections 8,9 . Here we synthesized data from 108 eCO 2 experiments and found that the effect of eCO 2 on SOC stocks is best explained by a negative relationship with plant biomass: when plant biomass is strongly stimulated by eCO 2 , SOC storage declines; conversely, when biomass is weakly stimulated, SOC storage increases. This trade-off appears to be related to plant nutrient acquisition, in which plants increase their biomass by mining the soil for nutrients, which decreases SOC storage. We found that, overall, SOC stocks increase with eCO 2 in grasslands (8 ± 2 per cent) but not in forests (0 ± 2 per cent), even though plant biomass in grasslands increase less (9 ± 3 per cent) than in forests (23 ± 2 per cent). Ecosystem models do not reproduce this trade-off, which implies that projections of SOC may need to be revised.

Soil fungi link above- and belowground carbon (C) fluxes through their interactions with plants and contribute to C and nutrient dynamics through the production, turnover, and activity of fungal hyphae. Despite their importance to ecosystem processes, estimates of hyphal production and turnover rates are relatively uncommon, especially in temperate hardwood forests. We sequentially harvested hyphal ingrowth bags to quantify the rates of Dikarya (Ascomycota and Basidiomycota) hyphal production and turnover in three hardwood forests in the Midwestern United States, where plots differed in their abundance of arbuscular (AM)- vs. ectomycorrhizal (ECM)-associated trees. Hyphal production rates increased linearly with the percentage of ECM trees and annual production rates were 66% higher in ECM- than AM-dominated plots. Hyphal turnover rates did not differ across the mycorrhizal gradient (plots varying in their abundance of AM vs. ECM trees), suggesting that the greater fungal biomass in ECM-dominated plots relates to greater fungal production rather than slower fungal turnover. Differences in hyphal production across the gradient aligned with distinctly different fungal communities and activities. As ECM trees increased in dominance, fungi inside ingrowth bags produced more extracellular enzymes involved in degrading nitrogen (N)-bearing relative to C-bearing compounds, suggesting greater fungal (and possibly plant) N demand in ECM-dominated soils. Collectively, our results demonstrate that shifts in temperate tree species composition that result in changes in the dominant type of mycorrhizal association may have strong impacts on Dikarya hyphal production, fungal community composition and extracellular enzyme activity, with important consequences for soil C and N cycling., (© 2020 The Authors. Ecology published by Wiley Periodicals LLC on behalf of Ecological Society of America.)

Volatile nitrogen oxides (N 2 O, NO, NO 2 , HONO, …) can negatively impact climate, air quality, and human health. Using soils collected from temperate forests across the eastern United States, we show microbial communities involved in nitrogen (N) cycling are structured, in large part, by the composition of overstory trees, leading to predictable N-cycling syndromes, with consequences for emissions of volatile nitrogen oxides to air. Trees associating with arbuscular mycorrhizal (AM) fungi promote soil microbial communities with higher N-cycle potential and activity, relative to microbial communities in soils dominated by trees associating with ectomycorrhizal (ECM) fungi. Metagenomic analysis and gene expression studies reveal a 5 and 3.5 times greater estimated N-cycle gene and transcript copy numbers, respectively, in AM relative to ECM soil. Furthermore, we observe a 60% linear decrease in volatile reactive nitrogen gas flux (NO y  ≡ NO, NO 2 , HONO) as ECM tree abundance increases. Compared to oxic conditions, gas flux potential of N 2 O and NO increase significantly under anoxic conditions for AM soil (30- and 120-fold increase), but not ECM soil-likely owing to small concentrations of available substrate ( NO 3 - ) in ECM soil. Linear mixed effects modeling shows that ECM tree abundance, microbial process rates, and geographic location are primarily responsible for variation in peak potential NO y flux. Given that nearly all tree species associate with either AM or ECM fungi, our results indicate that the consequences of tree species shifts associated with global change may have predictable consequences for soil N cycling., (© 2020 The Authors. Global Change Biology published by John Wiley & Sons Ltd.)

Globally, soils store two to three times as much carbon as currently resides in the atmosphere, and it is critical to understand how soil greenhouse gas (GHG) emissions and uptake will respond to ongoing climate change. In particular, the soil-to-atmosphere CO 2 flux, commonly though imprecisely termed soil respiration (R S ), is one of the largest carbon fluxes in the Earth system. An increasing number of high-frequency R S measurements (typically, from an automated system with hourly sampling) have been made over the last two decades; an increasing number of methane measurements are being made with such systems as well. Such high frequency data are an invaluable resource for understanding GHG fluxes, but lack a central database or repository. Here we describe the lightweight, open-source COSORE (COntinuous SOil REspiration) database and software, that focuses on automated, continuous and long-term GHG flux datasets, and is intended to serve as a community resource for earth sciences, climate change syntheses and model evaluation. Contributed datasets are mapped to a single, consistent standard, with metadata on contributors, geographic location, measurement conditions and ancillary data. The design emphasizes the importance of reproducibility, scientific transparency and open access to data. While being oriented towards continuously measured R S , the database design accommodates other soil-atmosphere measurements (e.g. ecosystem respiration, chamber-measured net ecosystem exchange, methane fluxes) as well as experimental treatments (heterotrophic only, etc.). We give brief examples of the types of analyses possible using this new community resource and describe its accompanying R software package., (© 2020 The Authors. Global Change Biology published by John Wiley & Sons Ltd.)

Objective  Outside pregnancy, nitrofurantoin, ciprofloxacin and sulfamethoxazole-trimethoprim (SMZ-TMP) are first-line therapy (FLT) for lower urinary tract infections (LUTIs). Optimal antibiotics for LUTI have been extrapolated based on expert opinion. Progression to pyelonephritis and adverse obstetric outcomes were compared between women who received FLT and those given alternative antibiotics. Methods  This study includes a retrospective cohort of women with LUTI, including asymptomatic bacteriuria and acute cystitis at single health care system from July 2013 to May 2019. Women receiving FLT, defined as nitrofurantoin or SMZ-TMP, were compared with those receiving nonfirst-line therapy (nFLT). Primary outcome was progression to pyelonephritis. Secondary outcomes included pyelonephritis-related anemia, sepsis, length of stay, preterm birth (PTB), and low birth weight (LBW). Logistic regression was used to calculate odds of outcomes. Results  Of 476 women, 336 (70.6%) received FLT and 140 (29.4%) received nFLT. Women receiving FLT were more likely having BMI ≥ 40 ( p  = 0.04). Progression to pyelonephritis did not differ (5.8 vs. 8.2%; p  = 0.44), nor did other pyelonephritis-related outcomes. After controlling for confounders, no difference in odds of progression to pyelonephritis was seen (adjusted odds ratio [aOR] 1.02, 95% confidence interval [CI] 0.42, 2.49). FLT was not associated with PTB or LBW (aOR 0.60, 95% CI 0.29, 1.26) after controlling for confounders. Conclusion  Receipt of antibiotics other than nitrofurantoin or SMZ-TMP for LUTI in pregnancy was not associated with increased risk of progression to pyelonephritis, PTB, or LBW., (The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial-License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. ( https://creativecommons.org/licenses/by-nc-nd/4.0/ ).)

Objectives: The Accreditation Council for Graduate Medical Education (ACGME) milestones for obstetrics and gynecology (OB/GYN) residents include obstetrical technical skills. We sought to describe resident experience with surgical obstetrics and comfort performing procedures independently postgraduation., Study Design: An anonymous 27-question e-survey was sent to OB/GYN residents in United States in March 2018, using the Council of Resident Education in Obstetrics and Gynecology coordinator listserv. Complex obstetric procedures included: forceps-assisted vaginal delivery (FAVD) and vacuum-assisted vaginal delivery (VAVD), cerclage, breech second twin, breech delivery, perineal repairs, and cesarean hysterectomy. Technical skill questions included experience as primary surgeon, comfort performing procedures independently, and for 4th year residents-comfort performing procedures postresidency. Demographic information was queried. Descriptive statistics was used to analyze responses., Results: A total of 417 residents completed the survey. Respondents were 88% female, 75% from academic programs, and 48% postgraduate year 3 and 4. Among all residents, many had been primary surgeon in operative vaginal deliveries (51% FAVD, 72% VAVD), fewer for breech vaginal delivery (21%), breech second twin (34%), cesarean hysterectomy (21%), and 4th degree repairs (37%). All 4th-year respondents stated that they would feel comfortable performing either VAVD or FAVD postresidency. Note that 17, 33, 28, and 74% would not feel comfortable performing a 4th degree repair, cesarean hysterectomy, breech second twin, and breech vaginal delivery, respectively, postresidency., Conclusion: Despite ACGME recommendations, data suggest that many graduating residents may not be comfortable with these complex procedures., Competing Interests: None declared., (Thieme. All rights reserved.)

The FLUXNET2015 dataset provides ecosystem-scale data on CO 2 , water, and energy exchange between the biosphere and the atmosphere, and other meteorological and biological measurements, from 212 sites around the globe (over 1500 site-years, up to and including year 2014). These sites, independently managed and operated, voluntarily contributed their data to create global datasets. Data were quality controlled and processed using uniform methods, to improve consistency and intercomparability across sites. The dataset is already being used in a number of applications, including ecophysiology studies, remote sensing studies, and development of ecosystem and Earth system models. FLUXNET2015 includes derived-data products, such as gap-filled time series, ecosystem respiration and photosynthetic uptake estimates, estimation of uncertainties, and metadata about the measurements, presented for the first time in this paper. In addition, 206 of these sites are for the first time distributed under a Creative Commons (CC-BY 4.0) license. This paper details this enhanced dataset and the processing methods, now made available as open-source codes, making the dataset more accessible, transparent, and reproducible.

This article describes the history, inspiration, goals, and outputs of the 2019 APA Presidential Initiative on Deep Poverty. Historically, psychologists have contributed to understanding the causes and consequences of poverty, as well as in interventions to ameliorate its effects. Less attention has been paid, however, to psychologists' unique contributions to studying and ending deep poverty, despite psychology's obvious relevance to the topic. As such, a working group was formed to develop the Deep Poverty Initiative (DPI), which had 3 main goals to engage psychologists in the fight against deep poverty: (a) change attitudes and perceptions about people living in deep poverty, (b) change policy to increase support for safety-net programs, and (c) change practices by increasing the use of psychological science and practice to build the capacity of poverty-serving organizations. First, 5 main themes from the psychological literature on deep poverty were identified by the DPI working group as crucial to changing attitudes. Compared to poverty, deep poverty was found to be especially dehumanizing, difficult to exit, and complex to solve, while also causing additional physical and psychological harm and obscuring human strengths. With this information as a basis, the working group mobilized psychologists to use the psychological science, along with their skills and positions within communities, to achieve the remaining goals of the initiative. Specific outputs, lessons learned, and suggestions for future work to continue to bring psychologists to the fight against deep poverty are given. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Objective: Chorioamnionitis (CAM) is associated with postcesarean (CS) infectious morbidity (IM). Beta-lactam antibiotics (BLA) are used to treat CAM. It is uncertain if women who cannot receive BLA attain similar benefit from treatment of CAM with non-BLA., Study Design: Retrospective cohort of women with CAM is delivered by CS in the maternal-fetal medicine units CS registry. We compared IM in women who received BLA versus women who received non-BLA. The primary outcome was a composite of endometritis, wound complication, necrotizing fasciitis, septic pelvic thrombophlebitis, and pelvic abscess. Multivariable logistic regression estimated odds ratios for the association of non-BLA treatment with IM outcomes., Results: A total of 3,063 (93%) women received BLA, and 232 (7%) received non-BLA. Groups had similar rates of composite post-CS IM (10.6 vs. 12.1%, p  = 0.5). After adjusting for confounders, treatment of CAM with non-BLA was not associated with post-CS IM (adjusted odds ratio [AOR] 1.1, 95% confidence interval [CI] 0.6-1.7), endometritis (AOR 1.1, 95% CI 0.7-1.8), or wound complications (AOR 1.2, 95% CI 0.5-3.2)., Conclusion: Women with CAM who receive non-BLA and require CS may not be at increased risk of postoperative infections complications, compared to women who receive BLA., Competing Interests: None declared., (Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.)

Non-structural carbohydrate (NSC) pools fluctuate based on the interplay between photosynthesis, demand from various carbon (C) sinks and tree hydraulic status. Thus, it has been hypothesized that tree species with isohydric stomatal control (i.e., trees that close stomata rapidly in response to drought) rely heavily on NSC pools to sustain metabolism, which can lead to negative physiological consequences such as C depletion. Here, we seek to use a species' degree of isohydry or anisohydry as a conceptual framework for understanding the interrelations between photosynthetic C supply, hydraulic damage and fluctuations in NSC pools. We conducted a 6-week experimental drought, followed by a 6-week recovery period, in a greenhouse on seven tree species that span the spectrum from isohydric to anisohydric. Throughout the experiment, we measured photosynthesis, hydraulic damage and NSC pools. Non-structural carbohydrate pools were remarkably stable across species and tissues-even highly isohydric species that drastically reduced C assimilation were able to maintain stored C. Despite these static NSC pools, we still inferred an important role for stored C during drought, as most species converted starches into sugars during water stress (and back again post-drought). Finally, we did not observe any linkages between C supply, hydraulic damage and NSC pools, indicating that NSC was maintained independent of variation in photosynthesis and hydraulic function. Our results advance the idea that C depletion is a rare phenomenon due to either active maintenance of NSC pools or sink limitation, and thus question the hypothesis that reductions in C assimilation necessarily lead to C depletion., (© The Author(s) 2019. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Objective: To estimate the incidence of and define risk factors for postpartum infectious complications after vaginal birth after cesarean (VBAC) complicated by chorioamnionitis., Study Design: A secondary analysis of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Maternal-Fetal Medicine Unit Cesarean Registry was performed. The primary outcome was a composite of postpartum infection: endometritis, sepsis, pelvic abscess, urinary tract infection, necrotizing fasciitis, and septic pelvic thrombophlebitis. Peripartum predictors were compared using parametric and nonparametric tests, as appropriate, and multivariate predictors assessed using logistic regression., Results: A total of 559 subjects had chorioamnionitis in labor and a successful VBAC. Twenty-four (4.3%) subjects experienced the primary outcome, mainly due to endometritis (19/24). Significant factors included preterm delivery <32 weeks (odds ratio [OR]: 3.05, 95% confidence interval [CI]: 1.32-7.06) and body mass index (BMI) ≥40 (OR: 4.63, 95% CI: 1.25-17.14). Receipt of postpartum antibiotics was protective against postpartum infection (OR: 0.28, 95% CI: 0.12-0.65). In multivariate analysis, preterm delivery <32 weeks, BMI ≥40, and receipt of postpartum antibiotics remained associated with postpartum infection., Conclusion: Nearly 5% of women with chorioamnionitis had a postpartum infectious complication after vaginal delivery, with higher rates in those delivering at <32 weeks and with prepregnancy BMI ≥40. Receipt of postpartum antibiotics decreased the odds of postpartum infection markedly., Competing Interests: None declared., (Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.)

Severe drought can cause lagged effects on tree physiology that negatively impact forest functioning for years. These "drought legacy effects" have been widely documented in tree-ring records and could have important implications for our understanding of broader scale forest carbon cycling. However, legacy effects in tree-ring increments may be decoupled from ecosystem fluxes due to (a) postdrought alterations in carbon allocation patterns; (b) temporal asynchrony between radial growth and carbon uptake; and (c) dendrochronological sampling biases. In order to link legacy effects from tree rings to whole forests, we leveraged a rich dataset from a Midwestern US forest that was severely impacted by a drought in 2012. At this site, we compiled tree-ring records, leaf-level gas exchange, eddy flux measurements, dendrometer band data, and satellite remote sensing estimates of greenness and leaf area before, during, and after the 2012 drought. After accounting for the relative abundance of tree species in the stand, we estimate that legacy effects led to ~10% reductions in tree-ring width increments in the year following the severe drought. Despite this stand-scale reduction in radial growth, we found that leaf-level photosynthesis, gross primary productivity (GPP), and vegetation greenness were not suppressed in the year following the 2012 drought. Neither temporal asynchrony between radial growth and carbon uptake nor sampling biases could explain our observations of legacy effects in tree rings but not in GPP. Instead, elevated leaf-level photosynthesis co-occurred with reduced leaf area in early 2013, indicating that resources may have been allocated away from radial growth in conjunction with postdrought upregulation of photosynthesis and repair of canopy damage. Collectively, our results indicate that tree-ring legacy effects were not observed in other canopy processes, and that postdrought canopy allocation could be an important mechanism that decouples tree-ring signals from GPP., (© 2019 John Wiley & Sons Ltd.)

Direct quantification of terrestrial biosphere responses to global change is crucial for projections of future climate change in Earth system models. Here, we synthesized ecosystem carbon-cycling data from 1,119 experiments performed over the past four decades concerning changes in temperature, precipitation, CO 2 and nitrogen across major terrestrial vegetation types of the world. Most experiments manipulated single rather than multiple global change drivers in temperate ecosystems of the USA, Europe and China. The magnitudes of warming and elevated CO 2 treatments were consistent with the ranges of future projections, whereas those of precipitation changes and nitrogen inputs often exceeded the projected ranges. Increases in global change drivers consistently accelerated, but decreased precipitation slowed down carbon-cycle processes. Nonlinear (including synergistic and antagonistic) effects among global change drivers were rare. Belowground carbon allocation responded negatively to increased precipitation and nitrogen addition and positively to decreased precipitation and elevated CO 2 . The sensitivities of carbon variables to multiple global change drivers depended on the background climate and ecosystem condition, suggesting that Earth system models should be evaluated using site-specific conditions for best uses of this large dataset. Together, this synthesis underscores an urgent need to explore the interactions among multiple global change drivers in underrepresented regions such as semi-arid ecosystems, forests in the tropics and subtropics, and Arctic tundra when forecasting future terrestrial carbon-climate feedback.

The extent to which ectomycorrhizal (ECM) fungi enable plants to access organic nitrogen (N) bound in soil organic matter (SOM) and transfer this growth-limiting nutrient to their plant host, has important implications for our understanding of plant-fungal interactions, and the cycling and storage of carbon (C) and N in terrestrial ecosystems. Empirical evidence currently supports a range of perspectives, suggesting that ECM vary in their ability to provide their host with N bound in SOM, and that this capacity can both positively and negatively influence soil C storage. To help resolve the multiplicity of observations, we gathered a group of researchers to explore the role of ECM fungi in soil C dynamics, and propose new directions that hold promise to resolve competing hypotheses and contrasting observations. In this Viewpoint, we summarize these deliberations and identify areas of inquiry that hold promise for increasing our understanding of these fundamental and widespread plant symbionts and their role in ecosystem-level biogeochemistry., (© 2019 The Authors. New Phytologist © 2019 New Phytologist Trust.)

The isohydry-anisohydry spectrum has become a popular way to characterize plant drought responses and recovery processes. Despite the proven utility of this framework for understanding the interconnected physiological changes plants undergo in response to water stress, new challenges have arisen pertaining to the traits and tradeoffs that underlie this concept. To test the utility of this framework for understanding hydraulic traits, drought physiology and recovery, we applied a 6 wk experimental soil moisture reduction to seven tree species followed by a 6 wk recovery period. Throughout, we measured hydraulic traits and monitored changes in gas exchange, leaf water potential, and hydraulic conductivity. Species' hydraulic traits were not coordinated, as some anisohydric species had surprisingly low resistance to embolism (P 50 ) and negative safety margins. In addition to widespread hydraulic damage, these species also experienced reductions in photosynthesis and stem water potential during water stress, and delayed recovery time. Given that we observed no benefit of being anisohydric either during or after drought, our results indicate the need to reconsider the traits and tradeoffs that underlie anisohydric behavior, and to consider the environmental, biological and edaphic processes that could allow this strategy to flourish in forests., (© 2019 The Authors. New Phytologist © 2019 New Phytologist Trust.)

Background: The use of trial of labor after cesarean delivery calculators in the prediction of successful vaginal birth after cesarean delivery gives physicians an evidence-based tool to assist with patient counseling and risk stratification. Before deployment of prediction models for routine care at an institutional level, it is recommended to test their performance initially in the institution's target population. This allows the institution to understand not only the overall accuracy of the model for the intended population but also to comprehend where the accuracy of the model is most limited when predicting across the range of predictions (calibration)., Objective: The purpose of this study was to compare 3 models that predict successful vaginal birth after cesarean delivery with the use of a single tertiary referral cohort before continuous model deployment in the electronic medical record., Study Design: All cesarean births for failed trial of labor after cesarean delivery and successful vaginal birth after cesarean delivery at an academic health system between May 2013 and March 2016 were reviewed. Women with a history of 1 previous cesarean birth who underwent a trial of labor with a term (≥37 weeks gestation), cephalic, and singleton gestation were included. Women with antepartum intrauterine fetal death or fetal anomalies were excluded. The probability of successful vaginal birth after cesarean delivery was calculated with the use of 3 prediction models: Grobman 2007, Grobman 2009, and Metz 2013 and compared with actual vaginal birth after cesarean delivery success. Each model's performance was measured with the use of concordance indices, Brier scores, and calibration plots. Decision curve analysis identified the range of threshold probabilities for which the best prediction model would be of clinical value., Results: Four hundred four women met the eligibility criteria. The observed rate of successful vaginal birth after cesarean delivery was 75% (305/404). Concordance indices were 0.717 (95% confidence interval, 0.659-0.778), 0.703 (95% confidence interval, 0.647-0.758), and 0.727 (95% confidence interval, 0.669-0.779), respectively. Brier scores were 0.172, 0.205, and 0.179, respectively. Calibration demonstrated that Grobman 2007 and Metz vaginal birth after cesarean delivery models were most accurate when predicted probabilities were >60% and were beneficial for counseling women who did not desire to have vaginal birth after cesarean delivery but had a predicted success rates of 60-90%. The models underpredicted actual probabilities when predicting success at <60%. The Grobman 2007 and Metz vaginal birth after cesarean delivery models provided greatest net benefit between threshold probabilities of 60-90% but did not provide a net benefit with lower predicted probabilities of success compared with a strategy of recommending vaginal birth after cesarean delivery for all women ., Conclusion: When 3 commonly used vaginal birth after cesarean delivery prediction models are compared in the same population, there are differences in performance that may affect an institution's choice of which model to use., (Copyright © 2019 Elsevier Inc. All rights reserved.)