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Summary: Nutrient limitation may constrain the ability of recovering and mature tropical forests to serve as a carbon sink. However, it is unclear to what extent trees can utilize nutrient acquisition strategies – especially root phosphatase enzymes and mycorrhizal symbioses – to overcome low nutrient availability across secondary succession.Using a large‐scale, full factorial nitrogen and phosphorus fertilization experiment of 76 plots along a secondary successional gradient in lowland wet tropical forests of Panama, we tested the extent to which root phosphatase enzyme activity and mycorrhizal colonization are flexible, and if investment shifts over succession, reflective of changing nutrient limitation. We also conducted a meta‐analysis to test how tropical trees adjust these strategies in response to nutrient additions and across succession.We find that tropical trees are dynamic, adjusting investment in strategies – particularly root phosphatase – in response to changing nutrient conditions through succession. These changes reflect a shift from strong nitrogen to weak phosphorus limitation over succession. Our meta‐analysis findings were consistent with our field study; we found more predictable responses of root phosphatase than mycorrhizal colonization to nutrient availability.Our findings suggest that nutrient acquisition strategies respond to nutrient availability and demand in tropical forests, likely critical for alleviating nutrient limitation. [ABSTRACT FROM AUTHOR]

Tropical ecosystems face escalating global change. These shifts can disrupt tropical forests' carbon (C) balance and impact root dynamics. Since roots perform essential functions such as resource acquisition and tissue protection, root responses can inform about the strategies and vulnerabilities of ecosystems facing present and future global changes. However, root trait dynamics are poorly understood, especially in tropical ecosystems. We analyzed existing research on tropical root responses to key global change drivers: warming, drought, flooding, cyclones, nitrogen (N) deposition, elevated (e) CO2, and fires. Based on tree species‐ and community‐level literature, we obtained 266 root trait observations from 93 studies across 24 tropical countries. We found differences in the proportion of root responsiveness to global change among different global change drivers but not among root categories. In particular, we observed that tropical root systems responded to warming and eCO2 by increasing root biomass in species‐scale studies. Drought increased the root: shoot ratio with no change in root biomass, indicating a decline in aboveground biomass. Despite N deposition being the most studied global change driver, it had some of the most variable effects on root characteristics, with few predictable responses. Episodic disturbances such as cyclones, fires, and flooding consistently resulted in a change in root trait expressions, with cyclones and fires increasing root production, potentially due to shifts in plant community and nutrient inputs, while flooding changed plant regulatory metabolisms due to low oxygen conditions. The data available to date clearly show that tropical forest root characteristics and dynamics are responding to global change, although in ways that are not always predictable. This synthesis indicates the need for replicated studies across root characteristics at species and community scales under different global change factors. [ABSTRACT FROM AUTHOR]

This article explores the significance of studying tropical forests and their responses to global change. It emphasizes the unique characteristics of tropical forests and their crucial role in the global carbon cycle. The article calls for research and model development to better understand the changing nature of these forests. It also discusses the importance of large-scale global change experiments and cross-site comparisons, as well as the complexity of plant, soil, and microbial responses. The document further highlights the need for inclusivity, collaboration, standardization, and the incorporation of local knowledge and partnerships with local communities in tropical forest research. [Extracted from the article]

Objective: Participation in regular exercise among post-secondary students is often low. Our cross-sectional study aimed to assess exercise levels, perceived barriers/motivators to exercise, and knowledge and use of exercise resources in graduate students. Participants: We recruited graduate students across various disciplines at a large Canadian university. Methods: Participants (n = 540) completed an anonymous mixed methods online survey. Results: Approximately 11% of participants reported not participating in any form of weekly exercise, and only 9.4% met the Canadian Physical Activity Guidelines. The most common barrier and motivator to exercise was time commitment and improving physical health, respectively. Some participants were aware of available exercise services but most did not use them. Suggestions for improving services included having graduate-dedicated exercise space and resources. Conclusions: Low exercise participation among graduate students may be due to a lack of education of available resources or a lack of existing resources that meet their specific needs. [ABSTRACT FROM AUTHOR]

Objective: To determine the impact of point-of-care ultrasound (POCUS)-guided resuscitation on clinical outcomes in adult patients with shock., Data Source: We searched MEDLINE, Embase, and unpublished sources from inception to December 2023., Study Selection: We included randomized controlled trials (RCTs) that examined the use of POCUS to guide resuscitation in patients with shock., Data Extraction: We collected data regarding study and patient characteristics, POCUS protocol, control group interventions, and outcomes., Data Synthesis: We identified 18 eligible RCTs. POCUS slightly influences physicians' plans for IV fluid (IVF) and vasoactive medication prescription (moderate certainty), but results in little to no changes in the administration of IVF (low to high certainty) or inotropes (high certainty). POCUS may result in no change in the number of CT scans performed (low certainty) but probably reduces the number of diagnostic echocardiograms performed (moderate certainty). POCUS-guided resuscitation probably reduces 28-day mortality (relative risk [RR] 0.88; 95% CI, 0.78-0.99), the duration of vasoactive medication (mean difference -0.73 d; 95% CI, -1.16 to -0.30), and the need for renal replacement therapy (RRT) (RR 0.80; 95% CI, 0.63-1.02) (low to moderate certainty evidence), and lactate clearance (high certainty evidence). POCUS-guided resuscitation may results in little to no difference in ICU or hospital admissions, ICU and hospital length of stay, and the need for mechanical ventilation (MV) (low to moderate certainty evidence). There is an uncertain effect on the risk of acute kidney injury and the duration of MV or RRT (very low certainty evidence)., Conclusions: POCUS-guided resuscitation in shock may yield important patient and health system benefits. Due to lack of sufficient evidence, we were unable to explore how the thresholds of operator competency, frequency, and timing of POCUS scans impact patient outcomes., Competing Interests: Dr. Slessarev’s institution received funding from the Canadian Institutes of Health Research (CIHR) project grant for randomized controlled trial related to ICU sedation; he received support for article research from the CIHR. The remaining authors have disclosed that they do not have any potential conflicts of interest., (Copyright © 2024 by the Society of Critical Care Medicine and Wolters Kluwer Health, Inc. All Rights Reserved.)

Purpose: To investigate outcome differences of intralesional triamcinolone acetonide (TA) injection for primary chalazia in children versus adults., Methods: A retrospective review of consecutive subjects with primary chalazion who received intralesional TA injection was conducted. A single investigator injected 0.05-0.15 mL of TA (40 mg/mL) intralesionally. Patients were stratified into the pediatric (<18 years old) and adult (≥ 18 years old) group. In both groups, the correlation of resolution time with chalazion size and TA dose was performed., Results: 17 children and 24 adults were enrolled, with a mean age of 7.4 ± 5.5 and 39.3 ± 16.7 years, respectively. Both groups had statistically similar baseline characteristics. There was no significant difference between the resolution time in the pediatric (18.2 ± 11.4 days) and adult (16.5 ± 11.0 days) group (P = 0.7). There were no significant complications from the TA injection. There was no significant correlation of resolution time to chalazion size (P = 0.7) nor TA dose (P = 0.3) in both groups., Conclusion: TA for the treatment of primary chalazion was equally effective in children and adults, without any significant complications, and the rate of clinical response did not appear to be dose-dependent.