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Electrochemically induced alkalinity enhancement increases coral growth rates in the local microenvironment
No full textCoral reef ecosystem health is rapidly declining worldwide. Restoration strategies such as propagation and outplanting aim to recover reef function but can be hindered by slow growth rates that limit scalability, necessitating technologies that accelerate growth to match the scale of reef degradation. Electrochemically induced alkalinity enhancement (eAE) offers a promising approach to locally enhance carbonate chemistry and favor calcification. We developed replicate eAE systems composed of steel cathodes and a platinized anode housed within an evacuation pump to remove oxidative waste products. System performance was evaluated with carbonate chemistry incubations, microelectrode profiling, and two laboratory experiments with Acropora cervicornis and two heights of Pseudodiploria clivosa microfragments. The eAE system created an elevated pH microenvironment under 1 cm s-1 flow speeds, elevating pHT by 0.14 +/- 0.02 to 8.16 at the height of the 'short' 5 mm P. clivosa microfragments. At 3 cm s-1 flow speeds, pHT at 5 mm was 8.03, and under both flow speeds, pHT returned to bulk levels (8.02) at the height of the 15 mm P. clivosa and 50 mm A. cervicornis fragments. After sixty days, short P. clivosa microfragments exposed to eAE calcified 43% faster and had 53% greater planar tissue growth rates than controls. These enhancements occurred exclusively within the elevated pH boundary layer and did not extend to taller fragments (>= 15 mm), highlighting eAE's limited spatial extent. Our findings demonstrate eAE's potential to accelerate microfragment skirting rates. Integrating eAE into coral propagation pipelines could enhance nursery productivity, reduce generation times, and improve the overall scalability of reef restoration efforts
Low lateral right atrial scar: implications for the diagnosis of cavotricuspid isthmus block following ablation for atrial flutter
No full textHigh density 3D mapping for typical atrial flutter (AFL) ablation can provide a highly detailed voltage and activation map. Post-ablation mapping is typically used to identify cavotricuspid isthmus (CTI). Low voltage areas in the right atrium may yield misleading mapping results.
3D electroanatomic voltage and activation mapping of the right atrium (RA) was performed in 15 patients with typical AFL, using 3D high density mapping with a Halo or Pentaray catheter pre- and post-ablation. Activation and entrainment mapping confirmed CTI dependent AFL in all patients. Mean number of map points was 611 ± 312. Lateral low voltage areas were seen in 11 (73%) patients. Post-ablation activation map during CS pacing (n = 8) demonstrated latest activation on the lateral wall aligned with the low voltage areas (in 6 of 8 patients), and in 3 (27.3%) patients this was later than just lateral to the CTI ablation line, masquerading as a gap in the ablation line. However, bidirectional block was confirmed by differential pacing, widely split double potentials on the ablation line and non-inducibility. Failure to recognize this misleading activation map in 2 patients resulted in delivery of significantly more ablation lesions (34 vs. 19, p = 0.0007).
Areas of low voltage in the low lateral right atrium may lead to slow conduction and delayed activation in this area, in some cases even greater delay than just lateral to the CTI ablation line mimicking a gap in the ablation line. Comparing pre-ablation voltage to post-ablation activation map can identify areas of low voltage with slow conduction. The use of other maneuvers can prove bidirectional block and avoid further unnecessary RF delivery
Psychedelic therapeutics in psychiatric conditions
No full textInterest in psychedelic therapies is booming, with hundreds of studies in process. Despite the interest, there are no approved psychedelic treatments for any psychiatric condition. Further, the one large-scale development program using MDMA that reached the FDA was disapproved by the agency for reasons that could apply to clinical trials for classical psychedelics. We review the definitions of psychedelics, the current status of psychedelic therapies, conditions targeted, compounds under investigation, and the research/clinical strategies employed. Some treatment interventions include pharmacologically assisted psychotherapy, with both benefits and challenges associated with this strategy. There is debate about whether the psychedelic experience is a required fundamental element for therapeutic potential with the induced psychedelic state, rendering blinded clinical trials challenging. We address current societal issues, such as the deregulation of formerly illegal substances in some areas, that may affect development decisions. Our review also considers regulatory issues, including alternatives to blinded trials and whether some therapeutic targets, such as adjustment disorder, may pose hurdles if current regulatory standards are applied to these trials. The interest in psychedelic treatment is considerable, although the path forward has some complexities
Treatment Delays and Survival in Patients with Hepatocellular Carcinoma: A Multicenter Cohort Study
No full textAlthough treatment delays have been reported for several cancers, fewer studies have described the prevalence, contributing factors, and impact on survival in patients with HCC. We aimed to evaluate these aspects in a multicenter cohort.
We conducted a retrospective cohort study of patients diagnosed with HCC from 2010 to 2018 across 4 U.S. health systems. Treatment delay was defined as the first treatment >90 days after HCC diagnosis. Univariable and multivariable logistic regression analyses were performed to identify factors associated with treatment delays. The association between treatment delay and overall survival was evaluated using multivariable Cox regression analysis.
Among 1,561 eligible patients (median age 61.7 years, 75.0% men, 65.5% BCLC stage 0/A), treatment delays occurred in 357 (22.9%) patients. Treatment delays were most frequent with BCLC stage 0 (31.1%), followed by stage A (24.3%), stage B (22.6%), and stage C (13.6%). Men (OR 0.68, 95%CI 0.51 - 0.91) and patients with BCLC stage C HCC (vs stage A: OR 0.40, 95%CI 0.25 - 0.63) were less likely to experience delays, whereas those with BCLC stage 0 (vs stage A: OR 1.56, 95%CI 1.06 - 2.29) were more likely to experience delays. In a 6-month landmark analysis, survival did not differ between delayed vs. timely treatment (HR 1.09, 95%CI 0.87 - 1.37). Median survival from the 6-month landmark was 12.1 months (IQR: 5.5 - 23.3) and 14.6 months (IQR: 5.1 - 30.0) for the treatment delay and timely treatment groups, respectively.
Treatment delays exceeding 90 days occurred in over one-fifth of patients but were not associated with significant differences in survival
Tree diversity is changing across tropical Andean and Amazonian forests in response to global change
No full textClimate and atmospheric changes are impacting forest function and structure worldwide, but their effects on tropical forest diversity are unclear. Nowhere is the scientific challenge greater than in the Andes and the Amazon, which together include the world's most diverse forests. Here, using 406 permanent plots spanning four decades of intact lowland and montane forest dynamics, we test for long-term change in species richness and assess the influence of climate and other variables. We show that, at a continental scale, species richness appears stable, but this masks substantial regional variation. Species richness increased in Northern Andean and Western Amazon plots, yet declined in the Central Andes, Guyana Shield and Central-Eastern Amazon. Overall, warmer, drier and more seasonal forests lost species, while those at higher elevations, in less fragmented areas and with faster rates of tree turnover experienced increases. Region-specific drivers, particularly precipitation seasonality and demographic factors, modulated these trends. The results highlight the diverse ways in which Amazon-Andes forests are changing and underscore the critical need to preserve large-scale ecosystem integrity to maintain local tree diversity. By doing so, Northern Andean forests in particular could serve as an important refuge for species increasingly displaced by climate change
Digital technologies and the study of adaptation in small-scale fisheries
No full textEconomic experiments have led to important advances in our understanding of human adaptation in coupled social-environmental systems. However, these experiments may be costly, which limits their scale and even the external validity of their results. Digital technologies offer great potential to deploy economic experiments at scale, but this approach remains largely untested. Here, we evaluate the feasibility of using mobile computing platforms (smartphones, tablets, and computers) to deploy digital economic experiments that collect players’ response to environmental shocks. To do so, we developed a digital version of a well-studied natural resource harvesting game characterized by a renewable common-pool resource harvested in repeated iterations. We recorded a total of 3369 interactions with the outreach material, which led to a total of 740 rounds played; Only 11 players participated in the baseline and treatment games. We show that players’ behavior during digital experiments was qualitatively similar to responses observed during in-person games with fishers reported in the literature. Additionally, our exploratory analysis suggests that information about the risk of a shock is not enough to induce adaptation by players and that experiencing the shock is needed. Digital experiments provide an alternative path to study adaptation, but the approach presents its own limitations. Addressing the current limitations, particularly through strategies for engaging players, presents an opportunity for broad application of this approach to understand and inform adaptation to change.
•We leverage digital media platforms to deploy behavioral economic experiments.•“Digital experiments” elicit and capture responses similar to those recovered through in-person games.•Information about the risk of an environmental shock does not induce adaptation•Adaptation ensues only after a shock has occurred, and the effect dissipates quickly.•With its own drawbacks, digital experiments provide an alternative path to study adaptation.•Addressing current limitations presents an opportunity to understand and inform adaptation to change
Asynchronous Online Focus Groups: An Effective Approach to Engage Young Adult Women in Discussions on Mental Health Problems
No full textAs society becomes increasingly digital, qualitative research methods must continue to adapt and evolve to remain relevant and effective. This study aimed to evaluate the feasibility and utility of asynchronous online focus groups (AOFGs) as a platform to engage young women in discussions about mental health. The Learning Insights from Girls for Health (LIGHT) study utilized an AOFG to assess mental health problems and potential solutions among 52 young women, 18-25 years old, across the United States. This study analyzed survey data and transcripts from the LIGHT study to assess participants' perceptions and satisfaction with the AOFG approach, and to characterize participant engagement and interaction within the AOFGs. Over half (59.6%) of participants were "Extremely satisfied" with the approach, and 34.6% were "Somewhat satisfied." Participants highlighted Confidentiality, Flexibility, Connection and perspective sharing, and Equitable participation as strengths of the approach, and Lack of nonverbal and paraverbal cues, Disjointedness, and Prone to user and technical error as limitations. Two themes generated to characterize participant engagement and interactions in the AOFGs included (1) Engagement through storytelling elevates insights around mental health experiences and (2) Participant interactions included offering support in the form of advice, validation, and empathy. Results of this study indicate that AOFGs are a valuable platform for facilitating discussions about mental health in young women and are a practical and flexible approach to conducting qualitative research.</p
Discovering the dynamics of Sargassum rafts' centers of mass
No full textSince 2011, rafts of floating Sargassum seaweed have frequently obstructed the coasts of the Intra-Americas Seas. The motion of the rafts is represented by a high-dimensional nonlinear dynamical system. Referred to as the eBOMB model, this builds on the Maxey-Riley equation by incorporating interactions between clumps of Sargassum forming a raft and the effects of Earth's rotation. In practical applications, the motion of the centers of mass of the rafts is what matters; however, the law of motion remains undetermined in closed form, making a strong case for using machine learning to develop a low-dimensional model that enables numerical efficiency and facilitates conceptual understanding. In this exploratory work, we evaluate and contrast Long Short-Term Memory (LSTM) Recurrent Neural Networks (RNNs) and Sparse Identification of Nonlinear Dynamics (SINDy). In both cases, a physics-inspired closure modeling approach is taken rooted in eBOMB. Specifically, the LSTM model learns a mapping from a collection of eBOMB variables to the difference between raft center-of-mass and ocean velocities. The SINDy model's library of candidate functions is suggested by eBOMB variables and includes windowed velocity terms incorporating far-field effects of the carrying flow. Overall, the LSTM and SINDy models perform similarly, both operating better with tightly connected rafts but lose precision in more complex scenarios, such as wind effects and loosely connected rafts. LSTM is more effective with simple designs, utilizing fewer neurons and layers, but lacks interpretability, unlike SINDy, which identifies explicit functional dependencies. Including windowed velocity terms enhances modeling of nonlocal interactions, particularly in data sets with sparsely connected rafts
