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Lithium and sodium metal batteries continue to occupy the forefront of battery research. Their exceptionally high energy density and nominal voltages are highly attractive for cutting-edge energy storage applications. Anode-free metal batteries are also coming into the research spotlight offering improved safety and even higher energy densities than conventional metal batteries. However, uneven metal nucleation and growth which leads to dendrites continues to limit the commercialisation of conventional and anode-free metal batteries alike. This review connects models and theories from well-established fields in metallurgy and electrodeposition to both conventional and anode-free metal batteries. These highly applicable models and theories explain the driving forces of uneven metal growth and can inform future experiment design. Finally, the models and theories that are most relevant to each anode-related cell component are identified. Keeping these specific models and theories in mind will assist with rational design for these components., (© 2023 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

Background: Advances in medical treatments in recent years have contributed to an overall decline in HIV-related opportunistic infections and deaths in youth; however, mortality and morbidity rates in perinatally and nonperinatally infected adolescents and young adults (AYA) living with HIV remain relatively high today., Objective: The goal of this project was to assess the use, utility, and cost-effectiveness of PlusCare, a digital app for HIV case management in AYA living with HIV. The app supports routine case management tasks, such as scheduling follow-up visits, sharing documents for review and signature, laboratory test results, and between-visit communications (eg, encouraging messages)., Methods: We conducted a single-group mixed methods pre-post study with HIV case management programs in 2 large urban hospitals in the Boston metro area. Case management staff (case managers [CMs], N=20) and AYA living with HIV participants (N=45) took part in the study with access to PlusCare for up to 15 and 12 months, respectively., Results: The CMs and AYA living with HIV reported mean System Usability Scale scores of 51 (SD 7.9) and 63 (SD 10.6), respectively. Although marginally significant, total charges billed at 1 of the 2 sites compared with the 12 months before app use (including emergency, inpatient, and outpatient charges) decreased by 41% (P=.046). We also observed slight increases in AYA living with HIV self-reported self-efficacy in chronic disease management and quality of life (Health-Related Quality of Life-4) from baseline to the 12-month follow-up (P=.02 and P=.03, respectively) and increased self-efficacy from the 6- to 12-month follow-up (P=.02). There was no significant change in HIV viral suppression, appointment adherence, or medication adherence in this small-sample pilot study., Conclusions: Although perceived usability was low, qualitative feedback from CMs and use patterns suggested that direct messaging and timely, remote, and secure sharing of laboratory results and documents (including electronic signatures) between CMs and AYA living with HIV can be particularly useful and have potential value in supporting care coordination and promoting patient self-efficacy and quality of life., Trial Registration: ClinicalTrials.gov NCT03758066; https://clinicaltrials.gov/ct2/show/NCT03758066., (©Connie Fee, Julia Fuller, Carly E Guss, Elizabeth R Woods, Ellen R Cooper, Urmi Bhaumik, Dionne Graham, Sandra K Burchett, Olivia Dumont, Emily B Martey, Maria Narvaez, Jessica E Haberer, Dallas Swendeman, Shelagh A Mulvaney, Vikram S Kumar, Jonathan L Jackson, Y Xian Ho. Originally published in JMIR Formative Research (https://formative.jmir.org), 21.11.2022.)

Recent studies have highlighted the potential role of 11oxygenated (keto or hydroxy) androgens in human reproductive function with 11keto androgens circulating at concentrations comparable with testosterone in women and children. However, the intrinsic androgenic bioactivities of 11 keto and hydroxy androgens are not fully characterized. We therefore investigated the full androgen dose-response curves using complementary in vitro yeast and mammalian (HEK293) host cell bioassays of 11 keto and hydroxy derivatives of the potent androgens, testosterone (T) and dihydrotestosterone (DHT), compared with their parent non-11 oxygenated steroids together with the pro-androgen precursor (androstenedione (A 4 )) and metabolites (androstanedione, androsterone). For potent androgens, the mammalian HEK293 host cell bioassay was 22-138 times more sensitive than the yeast host cell bioassay. In both androgen bioassays, 11keto derivatives displayed androgenic bioactivity but significantly lower molar potency than their parent non-keto steroids. By contrast, the 11hydroxy derivatives had minimal or no androgenic bioactivity. In both bioassays 5α-reduction increased androgenic potency. These findings confirm that that 11keto androgens may contribute directly to androgen status in women, children, and other conditions apart from healthy eugonadal men whereas 11hydroxy androgens have negligible androgenic potency although it cannot be excluded that they may be converted to more potent androgens in vivo., (Crown Copyright © 2021. Published by Elsevier Ltd. All rights reserved.)

Objective: This study aimed to describe maternal characteristics and clinical outcomes of infants born to mothers with positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) tests during pregnancy at an urban, safety-net hospital in Boston., Study Design: We abstracted electronic chart data from 75 pregnant women with positive SARS-CoV-2 tests at any stage of gestation until 72 hours after birth who delivered consecutively between March 31 and August 6, 2020 at our center. We collected clinical data on maternal and infant characteristics, including testing, signs, and symptoms of coronavirus disease 2019 (COVID-19), delivery outcomes, newborn care practices (skin-to-skin care, location of care, and breastfeeding) and 30-day postdischarge infant emergency room visits and readmissions. We described categorical characteristics as percentages for this case series., Results: Among 75 pregnant women, 47 (63%) were Hispanic, 10 (13%) had hypertension, 23 (30%) had prepregnancy obesity, and 57 (76%) had symptomatic SARS-CoV-2 infection. Regarding birth outcomes, 32 (41%) had cesarean delivery and 14 (19%) had preterm birth. Among 75 infants, 5 (7%) had positive SARS-CoV-2 polymerase chain reaction tests in the first week of life, all of whom were born to Hispanic mothers with symptomatic SARS-CoV-2 infection and had clinical courses consistent with gestational age. Six (8%) infants visited the emergency department within 30 days of discharge; one was admitted with a non-COVID-19 diagnosis., Conclusion: At our urban, safety-net hospital among pregnant women with positive SARS-CoV-2 tests, 41% had a cesarean delivery and 19% had a preterm birth. Seven percent of infants had one or more positive SARS-CoV-2 tests and all infants had clinical courses expected for gestational age., Key Points: · Among 75 pregnant women with SARS-CoV-2 positive testing at our center, five infants (7%) had one or more SARS-CoV-2 positive tests in the first week of life.. · Infants with positive SARS-CoV-2 tests had clinical courses expected for gestational age.., Competing Interests: None declared., (Thieme. All rights reserved.)

Background: Massachusetts began newborn screening (NBS) for severe combined immunodeficiency (SCID) using measurement of T-cell receptor excision circles (TRECs) from dried blood spots., Objective: We describe developments and outcomes from the first 10 years of this program (February 1, 2009, to January 31, 2019)., Methods: TREC values, diagnostic, and outcome data from all patients screened for SCID were evaluated., Results: NBS of 720,038 infants prompted immunologic evaluation of 237 (0.03%). Of 237, 9 were diagnosed with SCID/leaky SCID (4% of referrals vs 0.001% general population). Another 7 were diagnosed with other combined immunodeficiencies, and 3 with athymia. SCID/leaky SCID incidence was approximately 1 in 80,000, whereas approximately 1 in 51,000 had severe T-cell lymphopenia for which definitive treatment was indicated. All patients with SCID/leaky SCID underwent hematopoietic cell transplant or gene therapy with 100% survival. One patient with athymia underwent successful thymus transplant. No known cases of SCID were missed. Compared with outcomes from the 10 years before SCID NBS, survival trended higher (9 of 9 vs 4 of 7), likely due to a lower rate of infection before treatment., Conclusions: Our data support a single NBS testing-and-referral algorithm for all gestational ages. Despite lower median TREC values in premature infants, the majority for all ages are well above the TREC cutoff and the algorithm, which selects urgent (undetectable TREC) and repeatedly abnormal TREC values, minimizes referral. We also found that low naïve T-cell percentage is associated with a higher risk of SCID/CID, demonstrating the utility of memory/naïve T-cell phenotyping as part of follow-up flow cytometry., (Copyright © 2021 American Academy of Allergy, Asthma & Immunology. All rights reserved.)

Androgens remain abused performance-enhancing drugs in sports. Technologies based on mass spectrometry can detect all forms of androgens but fail if the androgen represents a novel structure. A bioassay detects androgens based on function rather than structure. To date, there has been limited adoption of cell-based in vitro bioassays as a screening tool for nontargeted androgen detection because they require expert personnel and specialized equipment to perform. We now describe the development of a cell-free version of an androgen in vitro bioassay. Stage 1 involved in vitro transcription/translation reactions (IVTT) using a DNA template encoding an enhancer/androgen response element (ARE) regulatory region upstream of a minimal promoter that drives expression of a reporter protein. The assay detected testosterone across the concentration range of 106.7 to 0.0144 ng/ml (3.7 × 10 -7 to 5 × 10 -11 M), with an EC 50 of 6.63 ng/ml (23 nM). To reduce complexity, Stages 2-4 of development included just in vitro transcription (IVT) reactions, whereby the output was an RNA molecule. Stage 2 involved directly labelling the RNA molecule with fluorophore-labelled nucleotide triphosphates, Stage 3 involved reverse transcription-polymerase chain reaction (PCR) of the RNA molecule, and Stage 4 utilized an RNA aptamer, Mango II, as its RNA output. The Stage 4 product detected testosterone across the range of 106.7-0.0001 ng/ml (3.7 × 10 -7 to 5 × 10 -13 M), with an EC 50 of 0.04 ng/ml (0.155 nM). Further to this, we show that the Stage 4 product can detect other androgenic molecules. Relative to cell-based bioassays, the Stage 4 product is easy to perform and could be developed into a routine, high-throughput, nontargeted androgen screen., (© 2021 John Wiley & Sons, Ltd.)

Androgens, both steroidal and nonsteroidal in nature, are among the most commonly misused substances in competitive sports. Their recognized anabolic and performance enhancing effects through short- and long-term physiological adaptations make them popular. Androgens exist as natural steroids, or are chemically synthesized as anabolic androgenic steroids (AAS) or selective androgen receptor modulators (SARMs). In order to effectively detect misuse of androgens, targeted strategies are used. These targeted strategies rely heavily on mass spectrometry, and detection requires prior knowledge of the targeted structure and its metabolites. Although exquisitely sensitive, such approaches may fail to detect novel structures that are developed and marketed. A nontargeted approach to androgen detection involves the use of cell-based in vitro bioassays. Both yeast and mammalian cell androgen bioassays demonstrate a clear ability to detect AAS and SARMS, and if paired with high resolution mass spectrometry can putatively identify novel structures. In vitro cell bioassays are successfully used to characterize designer molecules and to detect exogenous androgens in biological samples. It is important to continue to develop new and effective detection approaches to prevent misuse of designer androgens, and in vitro bioassays represent a potential solution to nontargeted detection strategies., (© 2021 John Wiley & Sons, Ltd.)

Objective: To develop best-practice recommendations using thermal indices to determine work-to-rest ratios and facilitate further implementation of environmental monitoring for heat safety in secondary school athletics in the United States., Data Sources: A narrative review of the current literature on environmental monitoring for heat safety during athletics was conducted by content experts. A list of action-oriented recommendations was established from the narrative review and further refined using the Delphi method., Conclusions: Assessment of wet bulb globe temperature at the site of activity and throughout the duration of the event is recommended to assist clinicians and administrators in making appropriate decisions regarding the duration and frequency of activity and rest periods. Activity-modification guidelines should be predetermined and approved by stakeholders and should outline specific actions to be followed, such as the work-to-rest ratio, frequency and timing of hydration breaks, and adjustment of total exercise duration, equipment, and clothing. Furthermore, integration of exertional heat illness injury data with environmental condition characteristics is critical for the development of evidence-based heat safety guidelines for secondary school athletics. Athletic trainers play an essential role in conducting prospective injury data collection, recording onsite wet bulb globe temperature levels, and implementing recommendations to protect the health and safety of athletes., (© by the National Athletic Trainers' Association, Inc.)

Pediatric human immunodeficiency virus post-exposure prophylaxis is frequently indicated, but delays in medication receipt are common. Using plan-do-study-act cycles, we developed a multidisciplinary collaboration to reduce critical process delays in our pediatric emergency department. Interruptions decreased from a median 1 per month pre-intervention to zero per month during the intervention., (© The Author(s) 2020. Published by Oxford University Press on behalf of The Journal of the Pediatric Infectious Diseases Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Objective: The aim of this study was to describe the natural history of individuals with congenital HIV who develop JC virus (JCV) infection of the central nervous system (CNS)., Methods: We retrospectively evaluated individuals with congenital HIV who met criteria for progressive multifocal leukoencephalopathy (PML) or JCV granule cell neuronopathy (JCV GCN) at three major healthcare centres in the northeast USA. Data on adherence to combined antiretroviral therapy (cART), neurologic symptoms, serum markers of immunity and HIV infection, cerebrospinal fluid (CSF) analyses, radiographic features, modified Rankin Scale (mRS) scores and survival were collected from the electronic medical record up to a censoring date of 1 August 2020., Results: Among 10 adults with congenitally acquired HIV, nine were diagnosed with definitive PML and one was diagnosed with probable JCV GCN. Individuals presented at the time of their PML or JCV GCN diagnosis with a mean mRS of 2.0 (standard deviation 1.0). A premorbid mRS was documented for six patients and was zero in all cases. The most common risk factor was confirmed cART nonadherence in nine individuals. Five individuals with PML and one with JCV GCN died, with a latency from symptom onset to death of approximately 3 months for three individuals, and approximately 2 years for the remaining two., Conclusion: Youth-adulthood transition is a high-risk point for dropping off from medical care. The study of this timepoint in people living with HIV could help inform effective care in these individuals., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: The aim of this observational study was to determine the optimal timing of interleukin-6 receptor inhibitor (IL6ri) administration for coronavirus disease 2019 (COVID-19)., Methods: Patients with COVID-19 were given an IL6ri (sarilumab or tocilizumab) based on iteratively reviewed guidelines. IL6ri were initially reserved for critically ill patients, but after review, treatment was liberalized to patients with lower oxygen requirements. Patients were divided into two groups: those requiring ≤45% fraction of inspired oxygen (FiO 2 ) (termed stage IIB) and those requiring >45% FiO 2 (termed stage III) at the time of IL6ri administration. The main outcomes were all-cause mortality, discharge alive from hospital, and extubation., Results: A total of 255 COVID-19 patients were treated with IL6ri (149 stage IIB and 106 stage III). Patients treated in stage IIB had lower mortality than those treated in stage III (adjusted hazard ratio (aHR) 0.24, 95% confidence interval (CI) 0.08-0.74). Overall, 218 (85.5%) patients were discharged alive. Patients treated in stage IIB were more likely to be discharged (aHR 1.43, 95% CI 1.06-1.93) and were less likely to be intubated (aHR 0.43, 95% CI 0.24-0.79)., Conclusions: IL6ri administration prior to >45% FiO 2 requirement was associated with improved COVID-19 outcomes. This can guide clinical management pending results from randomized controlled trials., (Copyright © 2020 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Context: Interscholastic heat policies for football have not been evidence based. Therefore, their effectiveness in mitigating exertional heat illness has not been assessed., Objective: To discuss the development of the Georgia High School Association heat policy and assess the effectiveness of revised guidelines., Design: Descriptive epidemiology study., Setting: Georgia high schools., Patients or Other Participants: Interscholastic football players in grades 9 through 12., Main Outcome Measure(s): Heat syncope and heat exhaustion (HS/HE) illness rates (IRs) were calculated per 1000 athlete-exposures (AEs), and relative risk (RR) was calculated as a ratio of postpolicy (POST) IR divided by prepolicy (PRE) IR., Results: A total of 214 HS/HE cases (172 PRE, 42 POST) and 341 348 AEs (178 230 PRE, 163 118 POST) were identified. During the first 5 days of the PRE period, approximately 50% of HS/HE illnesses occurred; HS/HE IRs doubled when practice sessions increased from 2 to 2.5 hours and tripled for practices ≥3 hours. The HS/HE IRs in the PRE period increased from 0.44/1000 AEs for wet-bulb globe temperatures (WBGTs) of <82°F (<27.8°C) to >2.0/1000 AEs for WBGTs from 87°F (30.6°C) to 89.9°F (32.2°C). The RRs comparing PRE and POST policy periods were 0.29 for WBGTs of <82.0°F (<27.80°C), 0.65 for WBGTs from 82.0°F (27.8°C) to 86.9°F (30.5°C), and 0.23 for WBGTs from 87.0°F (30.6°C) to 89.9°F (32.2°C). No HS/HE illnesses occurred in the POST period for WBGTs at >90°F (>32.3°C)., Conclusions: Results from the PRE period guided the Georgia High School Association to revise its heat and humidity policy to include a mandated 5-day acclimatization period when no practices may exceed 2 hours and the use of WBGT-based activity-modification categories. The new policy reduced HS/HE IRs by 35% to 100%, depending on the WBGT category. Our results may be generalizable to other states with hot and humid climates similar to that of Georgia., (© by the National Athletic Trainers' Association, Inc.)

Both athletes and the general population use nutritional supplements. Athletes often turn to supplements hoping that consuming the supplement will help them be more competitive and healthy, while the general population hopes to improve body image or vitality. While many supplements contain ingredients that may have useful properties, there are supplements that are contaminated with compounds that are banned for use in sport or have been deliberately adulterated to fortify a supplement with an ingredient that will produce the advertised effect. In the present study, we have used yeast cell and mammalian cell androgen bioassays to characterize the androgenic bioactivity of 112 sports supplements available from the Australian market, either over the counter or via the Internet. All 112 products did not declare an androgen on the label as an included ingredient. Our findings show that six out of 112 supplements had strong androgenic bioactivity in the yeast cell bioassay, indicating products spiked or contaminated with androgens. The mammalian cell bioassay confirmed the strong androgenic bioactivity of five out of six positive supplements. Supplement 6 was metabolized to weaker androgenic bioactivity in the mammalian cells. Further to this, Supplement 6 was positive in a yeast cell progestin bioassay. Together, these findings highlight that nutritional supplements, taken without medical supervision, could expose or predispose users to the adverse consequences of androgen abuse. The findings reinforce the need to increase awareness of the dangers of nutritional supplements and highlight the challenges that clinicians face in the fast-growing market of nutritional supplements.

On August 1, 2001, Korey Stringer, a Pro Bowl offensive tackle for the Minnesota Vikings, became the first and to date the only professional American football player to die from exertional heat stroke (EHS). The death helped raise awareness of the dangers of exertional heat illnesses in athletes and prompted the development of heat safety policies at the professional, collegiate, and interscholastic levels. Despite the public awareness of this death, no published study has examined in detail the circumstances surrounding Stringer's fatal EHS. Using the well-documented details of the case, our study shows that Stringer's fatal EHS was the result of a combination of physiological limitations, organizational and treatment failings, and extreme environmental conditions. The COMfort FormulA (COMFA) energy budget model was used to assess the relative importance of several extrinsic factors on Stringer's EHS, including weather conditions, clothing insulation, and activity levels. We found that Stringer's high-intensity training in relation to the oppressive environmental conditions was the most prominent factor in producing dangerous, uncompensable heat stress conditions and that the full football uniform played a smaller role in influencing Stringer's energy budget. The extreme energy budget levels that led to the fatal EHS would have been avoided according to our modeling through a combination of reduced intensity and lower clothing insulation. Finally, a long delay in providing medical treatment made the EHS fatal. These results highlight the importance of modern heat safety guidelines that provide controls on extrinsic factors, such as the adjustment of duration and intensity of training along with protective equipment modifications based on environmental conditions and the presence of an emergency action plan focused on rapid recognition and immediate on-site aggressive cooling of EHS cases.

Sport supplements containing steroids never approved for therapeutic use have the potential for abuse by athletes. Most are marketed online and may contain undisclosed steroids yet are readily available despite lacking toxicological or pharmacological evaluation. In this study, 18 supplements purchased online underwent organic solvent extraction to isolate any steroids they contained. From the 18 supplements, 19 steroids were identified and for each, its intrinsic androgenic potency was determined by a yeast cell (Saccharomyces cerevisiae) androgen bioassay and its potential androgenic potency was determined by a liver (HuH7) cell androgen bioassay. The yeast bioassay showed that of the 19 steroids tested, 6 demonstrated strong intrinsic bioactivity, with 4 metabolically activated to even stronger androgens. Moreover, 4 steroids with moderate and 1 with intrinsically weak androgenic bioactivity were activated to more potent androgens. Finally, 8 steroids were metabolically inactivated or deactivated into weaker androgens. Our results show that Internet-sourced sport supplements may contain intrinsically strong androgens, or precursors that can be metabolized to them. These potentially potent pharmacologically active steroids are being used without regulatory control or consumer awareness of their potential adverse effects. Copyright © 2016 John Wiley & Sons, Ltd., (Copyright © 2016 John Wiley & Sons, Ltd.)

We report our experience with 2 infants with in utero HIV-1 infection who began very early combination antiretroviral therapy within 4 hours of birth. Further neonatal studies of antiretroviral pharmacokinetics (PKs), safety, efficacy and treatment strategies are critically needed for the development of more potent regimens for use in HIV-infected infants.

Context: Knowledge about the specific environmental and practice risks to participants in American intercollegiate football during preseason practices is limited. Identifying risks may mitigate occurrences of exertional heat illness (EHI)., Objective: To evaluate the associations among preseason practice day, session number, and wet bulb globe temperature (WBGT) and the incidence of EHI., Design: Descriptive epidemiology study., Setting: Sixty colleges and universities representing 5 geographic regions of the United States., Patients or Other Participants: National Collegiate Athletic Association football players., Main Outcome Measure(s): Data related to preseason practice day, session number, and WBGT. We measured WBGT every 15 minutes during the practice sessions and used the mean WBGT from each session in the analysis. We recorded the incidence of EHIs and calculated the athlete-exposures (AEs)., Results: A total of 553 EHI cases and 365 810 AEs were reported for an overall EHI rate of 1.52/1000 AEs (95% confidence interval [CI] = 1.42, 1.68). Approximately 74% (n = 407) of the reported EHI cases were exertional heat cramps (incidence rate = 1.14/1000 AEs; 95% CI = 1.03, 1.25), and about 26% (n = 146) were a combination of exertional heat syncope and heat exhaustion (incidence rate = 0.40/1000 AEs; 95% CI = 0.35, 0.48). The highest rate of EHI occurred during the first 14 days of the preseason period, and the greatest risk was during the first 7 days. The risk of EHI increased substantially when the WBGT was 82.0°F (27.8°C) or greater., Conclusions: We found an increased rate of EHI during the first 14 days of practice, especially during the first 7 days. When the WBGT was greater than 82.0°F (27.8°C), the rate of EHI increased. Sports medicine personnel should take all necessary preventive measures to reduce the EHI risk during the first 14 days of practice and when the environmental conditions are greater than 82.0°F (27.8°C) WBGT.

Objective: To determine whether the restriction of young sibling (<13 years) visitation in the neonatal intensive care unit (NICU) during the respiratory syncytial virus (RSV) season was associated with a reduction in the rate of RSV infection among NICU patients., Study Design: A retrospective chart review of all RSV positive infants from the 2001-2010 RSV seasons. The 2001-2006 RSV seasons (group 1) contained 639 admissions and the 2007-2010 (group 2, with sibling restriction) contained 461 admissions. Groups were compared by using the Fisher's Exact Test., Results: There was a reduction of RSV positive infants from 6.7% in Group 1 to 1.7% in Group 2 (P<0.0001). There was a reduction of symptomatic infants from the number of infants with symptomatic RSV infection from 23/639 infants with young sibling visitation to 2/461 (P<0.001)., Conclusion: Exclusion of young sibling visitors <13 years of age during RSV season was associated with a significant reduction in the number of RSV positive infants in the NICU.

Predicting the response of fine roots to increased atmospheric CO₂ concentration has important implications for carbon (C) and nutrient cycling in forest ecosystems. Root architecture is known to play an important role in how trees acquire soil resources in changing environments. However, the effects of elevated CO₂ on the fine-root architecture of trees remain unclear. We investigated the architectural response of fine roots exposed to 14 yr of CO₂ enrichment and 6 yr of nitrogen (N) fertilization in a Pinus taeda (loblolly pine) forest. Root traits reflecting geometry, topology and uptake function were measured on intact fine-root branches removed from soil monoliths and the litter layer. CO₂ enrichment resulted in the development of a fine-root pool that was less dichotomous and more exploratory under N-limited conditions. The per cent mycorrhizal colonization did not differ among treatments, suggesting that root growth and acclimation to elevated CO₂ were quantitatively more important than increased mycorrhizal associations. Our findings emphasize the importance of architectural plasticity in response to environmental change and suggest that changes in root architecture may allow trees to effectively exploit larger volumes of soil, thereby pre-empting progressive nutrient limitations., (© 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.)