Covert actions of epidural stimulation on spinal locomotor circuits.

Spinal circuitry produces the rhythm and patterning of locomotion. However, both descending and sensory inputs are required to initiate and adapt locomotion to the environment. Spinal cord injury (SCI) disrupts descending controls of the spinal cord, producing paralysis. Epidural stimulation (ES) is a promising clinical therapy for motor control recovery and is capable of reactivating the lumbar spinal locomotor networks, yet little is known about the effects of ES on locomotor neurons. Previously, we found that both sensory afferent pathways and serotonin exert mixed excitatory and inhibitory actions on lumbar interneurons involved in the generation of the locomotor rhythm, identified by the transcription factor Shox2. However, after chronic complete SCI, sensory afferent inputs to Shox2 interneurons become almost exclusively excitatory and Shox2 interneurons are supersensitive to serotonin. Here, we investigated the effects of ES on these SCI-induced changes. Inhibitory input from sensory pathways to Shox2 interneurons was maintained and serotonin supersensitivity was not observed in SCI mice that received daily sub-motor threshold ES. Interestingly, the effects of ES were maintained for at least three weeks after the ES was discontinued. In contrast, the effects of ES were not observed in Shox2 interneurons from mice that received ES after the establishment of the SCI-induced changes. Our results demonstrate mechanistic actions of ES at the level of identified spinal locomotor circuit neurons and the effectiveness of early treatment with ES on preservation of spinal locomotor circuitry after SCI, suggesting possible therapeutic benefits prior to the onset of motor rehabilitation.

Multinational Drug Survival Study of Omalizumab in Patients With Chronic Urticaria and Potential Predictors for Discontinuation.

Importance: Treating patients with chronic urticaria using omalizumab has been shown to be safe and effective in randomized clinical trials. Multinational studies on long-term omalizumab performance in chronic urticaria in clinical practice settings are lacking, especially on drug survival. Drug survival, which refers to the length of time that patients are treated with a specific drug, is a comprehensive outcome covering effectiveness, safety, and patient and physician preferences. Furthermore, little is known about the reasons and potential predictors for omalizumab discontinuation. Objective: To investigate omalizumab drug survival as well as reasons and potential predictors for discontinuation in a large, diverse population. Design, Setting, and Participants: This international multicenter cohort study was conducted at 14 Urticaria Centers of Reference and Excellence in 10 countries, including all patients with chronic urticaria from these centers who were ever treated with omalizumab. Main Outcomes and Measures: Drug survival analysis was performed to assess time to discontinuation. Patient characteristics and treatment protocols were investigated by Cox regression analysis to identify potential predictors for omalizumab discontinuation. Results: In 2325 patients with chronic urticaria who started omalizumab between June 2009 and July 2022, the mean (SD) age of the cohort was 42 (6) years, and 1650 participants (71%) were female. Overall omalizumab survival rates decreased from 76% to 39% after 1 to 7 years, respectively (median survival time, 3.3 [95 % CI, 2.9-4.0] years), primarily due to discontinuation from well-controlled disease in 576 patients (65%). Ineffectiveness and adverse effects were reasons for discontinuation in a far smaller proportion of patients, totaling 164 patients (18%) and 31 patients (4%), respectively. Fast treatment response was associated with higher rates of omalizumab discontinuation due to well-controlled disease (hazard ratio, 1.45 [95% CI, 1.20-1.75]), and disease duration of more than 2 years was associated with lower rates of discontinuation due to well-controlled disease (HR, 0.81 [95% CI, 0.67-0.98]). Immunosuppressive cotreatment at the start of omalizumab and autoimmune disease was associated with a higher risk for discontinuation due to ineffectiveness (HR, 1.65 [95% CI, 1.12-2.42]). The presence of spontaneous wheals (HR, 0.62 [95% CI, 0.41-0.93]) and access to higher dosages (HR, 0.40 [95% CI, 0.27-0.58) were both associated with a lower risk for discontinuation of omalizumab due to ineffectiveness. Conclusion and Relevance: This multinational omalizumab drug survival cohort study demonstrated that treatment of chronic urticaria with omalizumab in a clinical setting is effective and safe, and well-controlled disease is the main reason for treatment discontinuation. These findings on omalizumab drug survival rates and reasons and potential predictors for discontinuation may guide patients and physicians in clinical decision-making and expectation management. These results may call for the identification of biomarkers for chronic urticaria remission in complete responders to omalizumab treatment.

Putting Health care Where the Kids Are: US Public Attitudes About School-Based Health Centers.

BACKGROUND: School-based health centers (SBHCs) have been shown to offer substantial benefits to students but we know little about how the public thinks about them. We sought to assess US public attitudes about SBHCs and the provision of 7 health service lines-primary care, preventive care, vaccinations, preventive dental care, preventive vision care, mental health care, and nutrition counseling. METHODS: We administered a national online survey (N = 4196) of US adults using Lucid, a large, internet-based, opt-in panel to assess public attitudes about SBHCs as well as 7 commonly offered health services in SBHCs. We then used t-tests and weighted linear regression models to carry out our study objectives. RESULTS: Unadjusted analysis revealed that more than 2 in 3 respondents supported SBHCs in general as well as the provision of all health services in SBHCs. Regression analysis indicated that ideology, partisanship, and trust in public school principals served as consistent predictors of attitudes when controlling for demographic and health characteristics. The provision of vaccinations stood out as particularly controversial. Subanalysis of parents found even higher levels of support as well as a more subdued role of ideology and partisanship. CONCLUSIONS: The US public broadly supports the provision of health services in SBHCs. Our results should inform policymakers, advocates, and providers seeking to improve access to health care among school-aged children, particularly for underserved populations. Increasing knowledge about SBHCs and providing stable funding should be a priority. In the immediate future, SBHCs may offer an important buffer against ongoing Medicaid disenrollments.

Inaccuracies in provider directories persist for long periods of time.

A growing literature has identified substantial inaccuracies in consumer-facing provider directories, but it is unclear how long these inaccuracies persist. We re-surveyed inaccurately listed Pennsylvania providers (n = 5170) between 117 to 280 days after a previous secret-shopper survey. Overall, 19.0% (n = 983) of provider directory listings that had been identified as inaccurate were subsequently removed, 44.8% (n = 2316) of provider listings continued to show at least 1 inaccuracy, and 11.6% (n = 600) were accurate at follow-up. We were unable to reach 24.6% (n = 1271) of providers. Longer passage of time was associated with reductions in directory inaccuracies, particularly related to contact information, and to a lesser degree, with removal of inaccurate listings. We found substantial differences in corrective action by carrier. Together, these findings suggest persistent barriers to maintaining and updating provider directories, with implications for how well these tools can help consumers select health plans and access care.

Optimal Control of Collective Electrotaxis in Epithelial Monolayers.

Epithelial monolayers are some of the best-studied models for collective cell migration due to their abundance in multicellular systems and their tractability. Experimentally, the collective migration of epithelial monolayers can be robustly steered e.g. using electric fields, via a process termed electrotaxis. Theoretically, however, the question of how to design an electric field to achieve a desired spatiotemporal movement pattern is underexplored. In this work, we construct and calibrate an ordinary differential equation model to predict the average velocity of the centre of mass of a cellular monolayer in response to stimulation with an electric field. We use this model, in conjunction with optimal control theory, to derive physically realistic optimal electric field designs to achieve a variety of aims, including maximising the total distance travelled by the monolayer, maximising the monolayer velocity, and keeping the monolayer velocity constant during stimulation. Together, this work is the first to present a unified framework for optimal control of collective monolayer electrotaxis and provides a blueprint to optimally steer collective migration using other external cues.

Association between thrombus composition and first-pass recanalization after thrombectomy in acute ischemic stroke.

BACKGROUND: Achieving first-pass recanalization (FPR) has become the primary procedural objective during thrombectomy in acute ischemic stroke patients as it correlates with the best clinical outcome. Understanding factors contributing to FPR failures is essential to enhance FPR success rates. As the central target of thrombectomy, the thrombus itself may be a significant factor influencing FPR. OBJECTIVES: This study aimed to investigate the association between thrombus composition and FPR success rates. METHODS: In total, thrombi from 267 ischemic stroke patients were collected in the AZ Groeninge Hospital (Kortrijk, Belgium). Thrombus composition was determined via detailed histologic analysis of red blood cells (RBCs), fibrin, von Willebrand factor, platelets, leukocytes, citrullinated histone 3 (marker for neutrophil extracellular traps), and intracellular and extracellular DNA. FPR was defined as obtaining a modified thrombolysis in cerebral infarction (mTICI) score of 2c/3 after the first pass. RESULTS: An mTICI score of 2c/3 was obtained in 180 patients, which was achieved via a successful FPR procedure in 126 cases or after multiple passes in 54 cases. Interestingly, thrombi from FPR cases had a different composition from thrombi that needed multiple passes to obtain an mTICI score of 2c/3. FPR thrombi contained significantly more RBCs (P = .0264), less fibrin (P = .0196), and less extracellular DNA (P = .0457). CONCLUSION: Our results indicate that thrombi characterized by lower RBC content, higher fibrin levels, and increased extracellular DNA are less likely to result in an FPR. These results are important to guide future research aiming at improving procedures or technologies to obtain FPR rates in RBC-poor thrombi.

Tumour necrosis is a valuable histopathological prognostic parameter in melanomas of the vulva and vagina.

Vulvar and vaginal melanomas (VVMs) are rare and aggressive malignancies with limited prognostic models available and there is no standard reporting protocol. VVMs were selected from six tertiary Canadian hospitals from 2000-2021, resected from patients aged ≥18 years, with 6 months or longer follow-up data, and confirmation of melanocytic differentiation by at least two immunohistochemical markers. Cases were reviewed by pathologists to identify histological biomarkers. Survival outcomes were tested with Kaplan-Meier log-rank, univariate Cox, and multivariate Cox regression. There were 79 VVMs with median follow-up at 26 months. Univariate analysis revealed that tumour necrosis, tumour ulceration, positive lymph nodes, and metastasis at diagnosis were significantly associated with disease-specific mortality, progression, and metastasis. Multivariate analysis identified tumour necrosis as an independent prognostic factor for disease-specific mortality (HR 4.803, 95% CI 1.954-11.803, p<0.001), progression (HR 2.676, 95% CI 1.403-5.102, p=0.003), and time-to-metastasis for non-metastatic patients at diagnosis (HR 3.761, 95%CI 1.678-8.431, p=0.001). Kaplan-Meier survival analyses demonstrated that tumour necrosis was a poor prognostic factor for disease-specific, progression-free, and metastasis-free survival (p<0.001 for all comparisons). Vaginal melanomas displayed decreased survival compared to vulvar or clitoral melanomas. This study identifies tumour necrosis as an independent prognostic factor for VVMs. Vaginal melanomas specifically showed worse survival outcomes compared to vulvar or clitoral melanomas, consistent with previously reported findings in the literature, emphasising the importance of differentiating between these primary tumour epicentres for prognostication and treatment planning in the care of genital melanoma patients.

Pain, disability, and quality of life in participants after concurrent onabotulinumtoxinA treatment of upper and lower limb spasticity: Observational results from the ASPIRE study.

INTRODUCTION: Upper and lower limb spasticity is commonly associated with central nervous system disorders including stroke, traumatic brain injury, multiple sclerosis, cerebral palsy, and spinal cord injury, but little is known about the concurrent treatment of upper and lower limb spasticity with botulinum toxins. OBJECTIVE: To evaluate onabotulinumtoxinA (onabotA) utilization and to determine if concurrent onabotA treatment of the upper and lower limbs has supported improvements in participants with spasticity. DESIGN: Sub-analysis of a 2-year, international, prospective, observational registry (ASPIRE, NCT01930786). SETTING: International clinic sites (54). PARTICIPANTS: Adult spasticity participants across etiologies, who received ≥1 concurrent onabotA treatment of the upper and lower limbs during the study. INTERVENTION: Participants were treated with onabotA at the clinician's discretion. OUTCOMES: Baseline characteristics and outcomes of disability (Disability Assessment Scale [DAS]), pain (Numeric Pain Rating Scale [NPRS]), participant satisfaction, physician satisfaction, and quality of life (QoL; Spasticity Impact Assessment [SIA]) were evaluated. Adverse events were monitored throughout the study. RESULTS: Of 744 participants enrolled, 730 received ≥1 dose of onabotA; 275 participants received treatment with onabotA in both upper and lower limbs during ≥1 session; 39.3% of participants were naïve to onabotA for spasticity. The mean (SD) total dose per treatment session ranged from 421.2 (195.3) to 499.6 (188.6) U. The most common baseline upper limb presentation was clenched fist (n = 194, 70.5%); lower limb was equinovarus foot (n = 219, 66.9%). High physician and participant satisfaction and improvements in pain, disability and QoL were reported after most treatments. Nine participants (3.3%) reported nine treatment-related adverse events; two participants (0.7%) reported three serious treatment-related severe adverse events. No new safety signals were identified. CONCLUSION: More than a third of enrolled participants received at least one concurrent onabotA treatment of the upper and lower limbs, with reduced pain, disability, and improved QoL after treatment, consistent with the established safety profile of onabotA for the treatment of spasticity.

Characterization of patients with atopic dermatitis based on flare patterns and severity of disease: A Danish population-based study.

BACKGROUND: Flare patterns are not routinely considered in the severity classification or in clinical decision-making of atopic dermatitis (AD), but frequent or severe flares may contribute considerably to the disease burden. OBJECTIVES: To characterize patients with AD in relation to their flare pattern and compare flare patterns to disease severity, life quality and treatment satisfaction. METHODS: Patients with AD from the Danish Skin Cohort were included if they had active AD with and available data on number of flare-ups within the last 12 months. Categorical variables were presented as frequencies and percentages, whereas numerical variables were presented as median and interquartile ranges (IQR). Between-group differences were tested with chi-squared tests. RESULTS: A total of 1557 patients were included, with 57 reporting 0 flares, 698 (1-5 flares), 324 (6-10 flares) and 478 reporting >10 flares during the past 12 months. Both the severity measured by PO-SCORAD and the impairment of life quality measured by DLQI were higher among patients with more flares (median [IQR] PO-SCORAD: 13.0 [5.6-22.3], 29.7 [20.8-40.6], 36.3 [26.7-47.6]and 42.9 [30.7-55.6], respectively for the four flares strata, and median [IQR] DLQI: 1.0 [0.0-2.0], 3.0 [1.0-7.0], 4.0 [1.8-9.0] and 7.0 [3.0-11.0]). Satisfaction with the current treatment was generally higher among patients with no flares. However, 36.8%, 24.6% and 23.7% of patients with 1-5, 6-10 and >10 flares reported being extremely or very satisfied with their current treatment. CONCLUSIONS: Patients with many flares often report a higher severity and impairment of life quality compared to patients with fewer flares. Information on flaring could benefit treatment decisions, thereby decreasing undertreatment of patients with mild AD but severe flaring.

US seniors' intention to vaccinate against RSV in fall and winter 2023-2024.

In the fall and winter of 2023-2024, the United States may experience a "tripledemic" of COVID-19, influenza, and respiratory syncytial virus (RSV) that may lead to 100 000 deaths. Seniors will be disproportionally affected. The newly released RSV vaccines for those age 60 years and over may reduce the number of deaths for the expected 6000 to 10 000 seniors expected to die from RSV alone. Using a large national survey, we queried Americans over age 60 about their RSV vaccination status and their intention to vaccinate this fall and winter. We found that 9% of seniors had already been vaccinated. Of the remaining unvaccinated, 42% indicated their intent to vaccinate. We found that those with higher levels of concerns for the disease, higher levels of self-assessed risk, believing that vaccines were safe and important, higher levels of trust in health institutions, and men were more likely to seek out vaccinations. Vaccine-hesitant respondents listed a lack of necessity, concerns about side effects and safety, and a lack of information as primary reasons. The large number of unvaccinated seniors will likely lead to an excessive number of hospitalizations and deaths as well as augmented social costs. Evidence-based mitigation measures tailored to seniors' concerns should be implemented immediately.

Epstein-Barr Virus Monitoring after an Allogeneic Hematopoietic Stem Cell Transplant: Review of the Recent Data and Current Practices in Canada.

Epstein-Barr virus-related post-transplantation lymphoproliferative disorder (EBV-PTLD) is a serious complication following hematopoietic stem cell transplantation (HSCT). A pre-emptive strategy using rituximab, which aims to manage patients early at the time of EBV reactivation to avoid PTLD, has been recommended by the most recent ECIL-6 guidelines in 2016. However, there is still a great heterogeneity of viral-load monitoring protocols, targeted patient populations, and pre-emptive treatment characteristics between centers, making precise EBV monitoring recommendations difficult. We conducted a literature review from the most recent publications between 1 January 2015 and 1 August 2023, to summarize the emerging data on EBV-PTLD prevention strategies in HSCT recipients, including the EBV-DNA threshold and use of rituximab. We also present the results of a survey of current practices carried out in 12 of the main HSCT centers across Canada. We confirm that pre-emptive rituximab remains an efficient strategy for EBV-PTLD prevention. However, there is an urgent need to perform prospective, randomized, multicentric trials with larger numbers of patients reflecting current practices to determine the best clinical conduct with regards to rituximab dosing, timing of treatment, and criteria to initiate treatments. Longer follow-ups will also be necessary to assess patients' long-term outcomes.

Research Note: Validation of a new differentiation approach using the commercial ASAPTM media to detect the Salmonella 441/014 vaccine strain.

Vaccination is one of the most important control tools to reduce Salmonella in poultry production. In order for a live vaccine to be licensed for field use it should be provided with the detection methods to differentiate it from field strains. This paper aims to describe the validation of an alternative method for the differentiation of the Salmonella 441/014 vaccine strain from field strains, using a chromogenic Media, ASAP from bioMérieux. The ASAP-based differentiation method was compared with already authorized methods, namely the Anicon SE Kylt PCR DIVA 1 assay and Ceva S-Check Salmonella differentiation kit, following the ISO 16140-6:2019 validation method guidelines. A Generalised Linear Model was fitted to the data to determine the inclusivity and exclusivity of differentiation methods (PCR Kylt vs. S-Check vs. ASAPTM). Statistical differences were based on a P-value level of < 0.05 (SPSS Inc., Chicago, IL). In this study, we show that the ASAP media was able to differentiate Salmonella Enteritidis vaccine strains from field strains, obtaining 100% agreement between the three differentiation assays. This differentiation approach is quicker, easier to deploy and cheaper as compared to alternative methods.

Tumorigenesis driven by the BRAFV600E oncoprotein requires secondary mutations that overcome its feedback inhibition of migration and invasion.

BRAFV600E mutation occurs in 46% of melanomas and drives high levels of ERK activity and ERK-dependent proliferation. However, BRAFV600E is insufficient to drive melanoma in GEMM models, and 82% of human benign nevi harbor BRAFV600E mutations. We show here that BRAFV600E inhibits mesenchymal migration by causing feedback inhibition of RAC1 activity. ERK pathway inhibition induces RAC1 activation and restores migration and invasion. In cells with BRAFV600E, mutant RAC1, overexpression of PREX1, PREX2, or PTEN inactivation restore RAC1 activity and cell motility. Together, these lesions occur in 48% of BRAFV600E melanomas. Thus, although BRAFV600E activation of ERK deregulates cell proliferation, it prevents full malignant transformation by causing feedback inhibition of cell migration. Secondary mutations are, therefore, required for tumorigenesis. One mechanism underlying tumor evolution may be the selection of lesions that rescue the deleterious effects of oncogenic drivers.

Thermodynamically Stable Functionalization of Microporous Aromatic Frameworks with Sulfonic Acid Groups by Inserting Methylene Spacers.

Porous aromatic frameworks (PAFs) are an auspicious class of materials that allow for the introduction of sulfonic acid groups at the aromatic core units by post-synthetic modification. This makes PAFs promising for proton-exchange materials. However, the limited thermal stability of sulfonic acid groups attached to aromatic cores prevents high-temperature applications. Here, we present a framework based on PAF-303 where the acid groups were added as methylene sulfonic acid side chains in a two-step post-synthetic route (SMPAF-303) via the intermediate chloromethylene PAF (ClMPAF-303). Elemental analysis, NMR spectroscopy, electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy were used to characterize both frameworks and corroborate the successful attachment of the side chains. The resulting framework SMPAF-303 features high thermal stability and an ion-exchange capacity of about 1.7 mequiv g-1. The proton conductivity depends strongly on the adsorbed water level. It reaches from about 10-7 S cm-1 for 33% RH to about 10-1 S cm-1 for 100% RH. We attribute the strong change to a locally alternating polarity of the inner surfaces. The latter introduces bottleneck effects for the water molecule and oxonium ion diffusion at lower relative humidities, due to electrolyte clustering. When the pores are completely filled with water, these bottlenecks vanish, leading to an unhindered electrolyte diffusion through the framework, explaining the conductivity rise.

Equine neuroaxonal dystrophy/degenerative myeloencephalopathy in Gypsy Vanner horses.

BACKGROUND: Equine neuroaxonal dystrophy/degenerative myeloencephalopathy (eNAD/EDM) is a neurodegenerative disease that primarily affects young, genetically predisposed horses that are deficient in vitamin E. Equine NAD/EDM has not previously been documented in Gypsy Vanner horses (GVs). OBJECTIVES: To evaluate: (1) the clinical phenotype, blood vitamin E concentrations before and after supplementation and pedigree in a cohort of GV horses with a high prevalence of neurologic disease suspicious for eNAD/EDM and (2) to confirm eNAD/EDM in GVs through postmortem evaluation. ANIMALS: Twenty-six GVs from 1 farm in California and 2 cases from the Midwestern U.S. METHODS: Prospective observational study on Californian horses; all 26 GVs underwent neurologic examination. Pre-supplementation blood vitamin E concentration was assessed in 17- GVs. Twenty-three were supplemented orally with 10 IU/kg of liquid RRR-alpha-tocopherol once daily for 28 days. Vitamin E concentration was measured in 23 GVs after supplementation, of which 15 (65%) had pre-supplementation measurements. Two clinically affected GVs from California and the 2 Midwestern cases had necropsy confirmation of eNAD/EDM. RESULTS: Pre-supplementation blood vitamin E concentration was ≤2.0 µg/mL in 16/17 (94%) of GVs from California. Post-supplementation concentration varied, with a median of 3.39 µg/mL (range, 1.23-13.87 µg/mL), but only 12/23 (52%) were normal (≥3.0 µg/mL). Normalization of vitamin E was significantly associated with increasing age (P = .02). Euthanized horses (n = 4) had eNAD/EDM confirmed at necropsy. CONCLUSIONS AND CLINICAL IMPORTANCE: GVs could have a genetic predisposition to eNAD/EDM. Vitamin E supplementation should be considered and monitored in young GVs.

Polyester microfiber impacts on coastal sediment organic matter consumption.

As plastic pollution continues to accumulate at the seafloor, concerns around benthic ecosystem functionality heightens. This research demonstrates the systematic effects of polyester microfibers on seafloor organic matter consumption rates, an important benthic ecosystem function connected to multiple reactions and processes. We used a field-based assay to measure the loss of organic matter, both with and without polyester microfiber contamination. We identified sediment organic matter content, mud content, and mean grain size as the main drivers of organic matter consumption, however, polyester microfiber contamination decoupled ecosystem relationships and altered observed organic matter cycling dynamics. Organic matter consumption rates varied across horizontal and vertical spaces, highlighting that consumption and associated plastic effects are dependent on environmental heterogeneity at both small (within sites) and larger (between sites) scales. Our results emphasize the important role habitat heterogeneity plays in seafloor organic matter consumption and the associated effects of plastic pollution on ecosystem function.

"Candidatus Siderophilus nitratireducens": a putative nap-dependent nitrate-reducing iron oxidizer within the new order Siderophiliales.

Nitrate leaching from agricultural soils is increasingly found in groundwater, a primary source of drinking water worldwide. This nitrate influx can potentially stimulate the biological oxidation of iron in anoxic groundwater reservoirs. Nitrate-dependent iron-oxidizing (NDFO) bacteria have been extensively studied in laboratory settings, yet their ecophysiology in natural environments remains largely unknown. To this end, we established a pilot-scale filter on nitrate-rich groundwater to elucidate the structure and metabolism of nitrate-reducing iron-oxidizing microbiomes under oligotrophic conditions mimicking natural groundwaters. The enriched community stoichiometrically removed iron and nitrate consistently with the NDFO metabolism. Genome-resolved metagenomics revealed the underlying metabolic network between the dominant iron-dependent denitrifying autotrophs and the less abundant organoheterotrophs. The most abundant genome belonged to a new Candidate order, named Siderophiliales. This new species, "Candidatus Siderophilus nitratireducens," carries genes central genes to iron oxidation (cytochrome c cyc2), carbon fixation (rbc), and for the sole periplasmic nitrate reductase (nap). Using thermodynamics, we demonstrate that iron oxidation coupled to nap based dissimilatory reduction of nitrate to nitrite is energetically favorable under realistic Fe3+/Fe2+ and NO3-/NO2- concentration ratios. Ultimately, by bridging the gap between laboratory investigations and nitrate real-world conditions, this study provides insights into the intricate interplay between nitrate and iron in groundwater ecosystems, and expands our understanding of NDFOs taxonomic diversity and ecological role.